title: History of Cambodia

text: In the period 245–250 CE dignitaries of the Chinese Kingdom of Wu visited the Funan city Vyadharapura. Envoys Kang Tai and Zhu Ying defined Funan as to be a distinct Hindu culture. Trade with China had begun after the southward expansion of the Han Dynasty, around the 2nd century BCE Effectively Funan "controlled strategic land routes in addition to coastal areas" and occupied a prominent position as an "economic and administrative hub" between The Indian Ocean trade network and China, collectively known as the Maritime Silk Road. Trade routes, that eventually ended in distant Rome are corroborated by Roman and Persian coins and artefacts, unearthed at archaeological sites of 2nd and 3rd century settlements.


title: History of Cambodia

text: Funan is associated with myths, such as the Kattigara legend and the Khmer founding legend in which an Indian Brahman or prince named Preah Thaong in Khmer, Kaundinya in Sanskrit and Hun-t’ien in Chinese records marries the local ruler, a princess named Nagi Soma (Lieu-Ye in Chinese records), thus establishing the first Cambodian royal dynasty.


title: History of Cambodia

text: Scholars debate as to how deep the narrative is rooted in actual events and on Kaundinya's origin and status. A Chinese document, that underwent 4 alterations and a 3rd-century epigraphic inscription of Champa are the contemporary sources. Some scholars consider the story to be simply an allegory for the diffusion of Indic Hindu and Buddhist beliefs into ancient local cosmology and culture whereas some historians dismiss it chronologically.


title: History of Cambodia

text: Chinese annals report that Funan reached its territorial climax in the early 3rd century under the rule of king Fan Shih-man, extending as far south as Malaysia and as far west as Burma. A system of mercantilism in commercial monopolies was established. Exports ranged from forest products to precious metals and commodities such as gold, elephants, ivory, rhinoceros horn, kingfisher feathers, wild spices like cardamom, lacquer, hides and aromatic wood. Under Fan Shih-man Funan maintained a formidable fleet and was administered by an advanced bureaucracy, based on a "tribute-based economy, that produced a surplus which was used to support foreign traders along its coasts and ostensibly to launch expansionist missions to the west and south".


title: History of Cambodia

text: Historians maintain contradicting ideas about Funan's political status and integrity. Miriam T. Stark calls it simply Funan: [The]"notion of Fu Nan as an early "state"...has been built largely by historians using documentary and historical evidence" and Michael Vickery remarks: "Nevertheless, it is...unlikely that the several ports constituted a unified state, much less an 'empire'". Other sources though, imply imperial status: "Vassal kingdoms spread to southern Vietnam in the east and to the Malay peninsula in the west" and "Here we will look at two empires of this period...Funan and Srivijaya".


title: History of Cambodia

text: The question of how Funan came to an end is in the face of almost universal scholarly conflict impossible to pin down. Chenla is the name of Funan's successor in Chinese annals, first appearing in 616/617 CE


title: History of Cambodia

text: The archaeological approach to and interpretation of the entire early historic period is considered to be a decisive supplement for future research. The "Lower Mekong Archaeological Project" focuses on the development of political complexity in this region during the early historic period. LOMAP survey results of 2003 to 2005, for example, have helped to determine that "...the region's importance continued unabated throughout the pre-Angkorian period...and that at least three [surveyed areas] bear Angkorian-period dates and suggest the continued importance of the delta."


title: History of Cambodia

text: The History of the Chinese Sui dynasty contains records that a state called Chenla sent an embassy to China in 616 or 617 CE It says, that Chenla was a vassal of Funan, but under its ruler Citrasena-Mahendravarman conquered Funan and gained independence.


title: History of Cambodia

text: Most of the Chinese recordings on Chenla, including that of Chenla conquering Funan, have been contested since the 1970s as they are generally based on single remarks in the Chinese annals, as author Claude Jacques emphasised the very vague character of the Chinese terms 'Funan' and 'Chenla', while more domestic epigraphic sources become available. Claude Jacques summarises: "Very basic historical mistakes have been made" because "the history of pre-Angkorean Cambodia was reconstructed much more on the basis of Chinese records than on that of [Cambodian] inscriptions" and as new inscriptions were discovered, researchers "preferred to adjust the newly discovered facts to the initial outline rather than to call the Chinese reports into question".


title: History of Cambodia

text: The notion of Chenla's centre being in modern Laos has also been contested. "All that is required is that it be inland from Funan." The most important political record of pre-Angkor Cambodia, the inscription K53 from Ba Phnom, dated 667 CE does not indicate any political discontinuity, either in royal succession of kings Rudravarman, Bhavavarman I, Mahendravarman [Citrasena], Īśānavarman, and Jayavarman I or in the status of the family of officials who produced the inscription. Another inscription of a few years later, K44, 674 CE, commemorating a foundation in Kampot province under the patronage of Jayavarman I, refers to an earlier foundation in the time of King Raudravarma, presumably Rudravarman of Funan, and again there is no suggestion of political discontinuity.


title: History of Cambodia

text: The History of the T'ang asserts that shortly after 706 the country was split into Land Chenla and Water Chenla. The names signify a northern and a southern half, which may conveniently be referred to as Upper and Lower Chenla.


title: History of Cambodia

text: By the late 8th century Water Chenla had become a vassal of the Sailendra dynasty of Java – the last of its kings were killed and the polity incorporated into the Javanese monarchy around 790 CE. Land Chenla acquired independence under Jayavarman II in 802 CE


title: History of Cambodia

text: The Khmers, vassals of Funan, reached the Mekong river from the northern Menam River via the Mun River Valley. Chenla, their first independent state developed out of Funanese influence.


title: History of Cambodia

text: Ancient Chinese records mention two kings, Shrutavarman and Shreshthavarman who ruled at the capital Shreshthapura located in modern-day southern Laos. The immense influence on the identity of Cambodia to come was wrought by the Khmer Kingdom of Bhavapura, in the modern day Cambodian city of Kampong Thom. Its legacy was its most important sovereign, Ishanavarman who completely conquered the kingdom of Funan during 612–628. He chose his new capital at the Sambor Prei Kuk, naming it Ishanapura.


title: History of Cambodia

text: The six centuries of the Khmer Empire are characterised by unparalleled technical and artistic progress and achievements, political integrity and administrative stability. The empire represents the cultural and technical apogee of the Cambodian and Southeast Asian pre-industrial civilisation.


title: History of Cambodia

text: The Khmer Empire was preceded by Chenla, a polity with shifting centres of power, which was split into Land Chenla and Water Chenla in the early 8th century. By the late 8th century Water Chenla was absorbed by the Malays of the Srivijaya Empire and the Javanese of the Shailandra Empire and eventually incorporated into Java and Srivijaya.


title: History of Cambodia

text: Jayavarman II, ruler of Land Chenla, initiates a mythical Hindu consecration ceremony at Mount Kulen (Mount Mahendra) in 802 CE, intended to proclaim political autonomy and royal legitimacy. As he declared himself devaraja - god-king, divinely appointed and uncontested, he simultaneously declares independence from Shailandra and Srivijaya. He established Hariharalaya, the first capital of the Angkorean area near the modern town of Roluos.


title: History of Cambodia

text: Indravarman I (877–889) and his son and successor Yasovarman I (889–900), who established the capital Yasodharapura ordered the construction of huge water reservoirs (barays) north of the capital. The water management network depended on elaborate configurations of channels, ponds, and embankments built from huge quantities of clayey sand, the available bulk material on the Angkor plain. Dikes of the East Baray still exist today, which are more than long and wide. The largest component is the West Baray, a reservoir about long and across, containing approximately 50 million m of water.


title: History of Cambodia

text: Royal administration was based on the religious idea of the Shivaite Hindu state and the central cult of the sovereign as warlord and protector – the "Varman". This centralised system of governance appointed royal functionaries to provinces. The Mahidharapura dynasty – its first king was Jayavarman VI (1080 to 1107), which originated west of the Dângrêk Mountains in the Mun river valley discontinued the old "ritual policy", genealogical traditions and crucially, Hinduism as exclusive state religion. Some historians relate the empires' decline to these religious discontinuities.


title: History of Cambodia

text: The area that comprises the various capitals was spread out over around , it is nowadays commonly called Angkor. The combination of sophisticated wet-rice agriculture, based on an engineered irrigation system and the Tonlé Sap's spectacular abundance in fish and aquatic fauna, as protein source guaranteed a regular food surplus. Recent Geo-surveys have confirmed that Angkor maintained the largest pre-industrial settlement complex worldwide during the 12th and 13th centuries – some three quarters of a million people lived there. Sizeable contingents of the public workforce were to be redirected to monument building and infrastructure maintenance. A growing number of researchers relates the progressive over-exploitation of the delicate local eco-system and its resources alongside large scale deforestation and resulting erosion to the empires' eventual decline.


title: History of Cambodia

text: Under king Suryavarman II (1113–1150) the empire reached its greatest geographic extent as it directly or indirectly controlled Indochina, the Gulf of Thailand and large areas of northern maritime Southeast Asia. Suryavarman II commissioned the temple of Angkor Wat, built in a period of 37 years, its five towers representing Mount Meru is considered to be the most accomplished expression of classical Khmer architecture. However, territorial expansion ended when Suryavarman II was killed in battle attempting to invade Đại Việt. It was followed by a period of dynastic upheaval and a Cham invasion that culminated in the sack of Angkor in 1177.


title: History of Cambodia

text: King Jayavarman VII (reigned 1181–1219) is generally considered to be Cambodia's greatest King. A Mahayana Buddhist, he initiates his reign by striking back against Champa in a successful campaign. During his nearly forty years in power he becomes the most prolific monument builder, who establishes the city of Angkor Thom with its central temple the Bayon. Further outstanding works are attributed to him – Banteay Kdei, Ta Prohm, Neak Pean and Sra Srang. The construction of an impressive number of utilitarian and secular projects and edifices, such as maintenance of the extensive road network of Suryavarman I, in particular the royal road to Phimai and the many rest houses, bridges and hospitals make Jayavarman VII unique among all imperial rulers.


title: History of Cambodia

text: In August 1296, the Chinese diplomat Zhou Daguan arrived at Angkor and remained at the court of king Srindravarman until July 1297. He wrote a detailed report, "The Customs of Cambodia", on life in Angkor. His portrayal is one of the most important sources of understanding historical Angkor as the text offers valuable information on the everyday life and the habits of the inhabitants of Angkor.


title: History of Cambodia

text: The last Sanskrit inscription is dated 1327, and records the succession of Indrajayavarman by Jayavarman IX Parameshwara (1327–1336).


title: History of Cambodia

text: The empire was an agrarian state that consisted essentially of three social classes, the elite, workers and slaves. The elite included advisers, military leaders, courtiers, priests, religious ascetics and officials. Workers included agricultural labourers and also a variety of craftsman for construction projects. Slaves were often captives from military campaigns or distant villages. Coinage did not exist and the barter economy was based on agricultural produce, principally rice, with regional trade as an insignificant part of the economy.


title: History of Cambodia

text: The term "Post-Angkor Period of Cambodia", also the "Middle Period" refers to the historical era from the early 15th century to 1863, the beginning of the French Protectorate of Cambodia. Reliable sources – particularly for the 15th and 16th century – are very rare. A conclusive explanation that relates to concrete events manifesting the decline of the Khmer Empire has not yet been produced. However, most modern historians contest that several distinct and gradual changes of religious, dynastic, administrative and military nature, environmental problems and ecological imbalance coincided with shifts of power in Indochina and must all be taken into account to make an interpretation. In recent years, focus has notably shifted towards studies on climate changes, human–environment interactions and the ecological consequences.


title: History of Cambodia

text: Epigraphy in temples, ends in the third decade of the fourteenth, and does not resume until the mid-16th century. Recording of the Royal Chronology discontinues with King Jayavarman IX Parameshwara (or Jayavarma-Paramesvara) – there exists not a single contemporary record of even a king's name for over 200 years. Construction of monumental temple architecture had come to a standstill after Jayavarman VII's reign. According to author Michael Vickery there only exist external sources for Cambodia's 15th century, the Chinese Ming Shilu annals and the earliest Royal Chronicle of Ayutthaya. Wang Shi-zhen (王世貞), a Chinese scholar of the 16th century, remarked: "The official historians are unrestrained and are skilful at concealing the truth; but the memorials and statutes they record and the documents they copy cannot be discarded."


title: History of Cambodia

text: The central reference point for the entire 15th century is a Siamese intervention of some undisclosed nature at the capital Yasodharapura (Angkor Thom) around the year 1431. Historians relate the event to the shift of Cambodia's political centre southward to the region of Phnom Penh, Longvek and later Oudong.


title: History of Cambodia

text: Sources for the 16th century are more numerous. The kingdom is centred at the Mekong, prospering as an integral part of the Asian maritime trade network, via which the first contact with European explorers and adventurers does occur. Wars with the Siamese result in loss of territory and eventually the conquest of the capital Longvek in 1594. The Vietnamese on their "Southward March" reach Prei Nokor/Saigon at the Mekong Delta in the 17th century. This event initiates the slow process of Cambodia losing access to the seas and independent marine trade.


title: History of Cambodia

text: Siamese and Vietnamese dominance intensified during the 17th and 18th century, resulting in frequent displacements of the seat of power as the Khmer royal authority decreased to the state of a vassal. In the early 19th century with dynasties in Vietnam and Siam firmly established, Cambodia was placed under joint suzerainty, having lost its national sovereignty. British agent John Crawfurd states: "...the King of that ancient Kingdom is ready to throw himself under the protection of any European nation..." To save Cambodia from being incorporated into Vietnam and Siam, the Cambodians enlisted the aid of the Luzones/Lucoes (Filipinos from the Philippines) and Spaniards to restore the then Christianised King, Satha II, as monarch of Cambodia, this, after a Thai/Siamese invasion was repelled. However that was only temporary. Nevertheless, the future King, Ang Duong, also enlisted the aid of the French who were allied to the Spanish (As Spain was ruled by a French royal dynasty the Bourbons). The Cambodian king agreed to colonial France's offers of protection in order to restore the existence of the Cambodian monarchy, which took effect with King Norodom Prohmbarirak signing and officially recognising the French protectorate on 11 August 1863.


title: History of Cambodia

text: As the Vietnamese empire consolidated itself over the eastern mainland under Gia Long and Minh Mang, Cambodia fell to the Vietnamese invasion in 1811. The invasion was initially initiated by the ruling king, King Ang Chan II's (r. 1806–35) request to Gia Long to suppress his own brothers, Ang Snguon and Ang Em, who were in rebellion against him. The two brothers fled to Thailand, while Ang Chan became a Vietnamese vassal.


title: History of Cambodia

text: In 1820 Gia Long died and his fourth son Minh Mang inherited the throne. Both Minh Mang and his father were strong adherents of Confucianism, but Minh Mang was a sadistic isolationist and strong ruler. He removed the Viceroy of Cambodia and Saigon in 1832, triggered the pro-Catholic Lê Văn Khôi revolt against him in 1833. The Thai army, intended to support the rebellion, launched an offensive campaign against the Vietnamese on occupying Cambodia. This led Ang Chan to flee to Saigon, as Rama III promised to restore the Kingdom of Cambodia and punish the insolence of the Kingdom of Vietnam. In 1834, the rebellion in Southern Vietnam was suppressed, and Minh Mang ordered troops to launch the second invasion of Cambodia. This drove most of the Thai forces to the west and reinstalled Ang Chan as the puppet king in Phnom Penh, later succeeded by his daughter, Queen Ang Mey (r. 1835–41). Later that year, the Tây Thành Province was established, the Vietnamese occupied Cambodia result in direct Vietnamese control. For the next six years, the Vietnamese emperor had tried to force the Cambodians to adopt Vietnamese culture by cultural assimilation, a progress that historian David P. Chandler called "The Vietnamization of Cambodia."


title: History of Cambodia

text: The death of Minh Mang in early 1841 halted the Vietnamization of Cambodia. With 35,000 Thai troops, they took advantage the of dire situation in Vietnam, rushed into the Tây Thành Province, and were able to fend off Vietnamese counteroffensives in late 1845. The new Vietnamese emperor, Thieu Tri, readied to make peace with Siam, and in June 1847 a peace treaty was signed. The Kingdom of Cambodia under Ang Duong regained its independence after 36 years of brutal Vietnamese occupations and Siamese interventions.


title: History of Cambodia

text: In August 1863 King Norodom signed an agreement with the French placing the kingdom under the protection of France. The original treaty left Cambodian sovereignty intact, but French control gradually increased, with important landmarks in 1877, 1884, and 1897, until by the end of the century the king's authority no longer existed outside the palace. Norodom died in 1904, and his two successors, Sisowath and Monivong, were content to allow the French to control the country, but in 1940 France was defeated in a brief border war with Thailand and forced to surrender the provinces of Battambang and Angkor (the ancient site of Angkor itself was retained). King Monivong died in April 1941, and the French placed the obscure Prince Sihanouk on the throne as king, believing that the inexperienced 18-year old would be more pliable than Monivong's middle-aged son, Prince Monireth.


title: History of Cambodia

text: Cambodia's situation at the end of the war was chaotic. The Free French, under General Charles de Gaulle, were determined to recover Indochina, though they offered Cambodia and the other Indochinese protectorates a carefully circumscribed measure of self-government. Convinced that they had a "civilizing mission", they envisioned Indochina's participation in a French Union of former colonies that shared the common experience of French culture.


title: History of Cambodia

text: On 9 March 1945, during the Japanese occupation of Cambodia, young king Norodom Sihanouk proclaimed an independent Kingdom of Kampuchea, following a formal request by the Japanese. Shortly thereafter the Japanese government nominally ratified the independence of Cambodia and established a consulate in Phnom Penh. The new government did away with the romanisation of the Khmer language that the French colonial administration was beginning to enforce and officially reinstated the Khmer script. This measure taken by the short-lived governmental authority would be popular and long-lasting, for since then no government in Cambodia has tried to romanise the Khmer language again.


title: History of Cambodia

text: After Allied military units entered Cambodia, the Japanese military forces present in the country were disarmed and repatriated. The French were able to reimpose the colonial administration in Phnom Penh in October the same year.


title: History of Cambodia

text: Sihanouk's "royal crusade for independence" resulted in grudging French acquiescence to his demands for a transfer of sovereignty. A partial agreement was struck in October 1953. Sihanouk then declared that independence had been achieved and returned in triumph to Phnom Penh. As a result of the Geneva Conference on Indochina, Cambodia was able to bring about the withdrawal of the Viet Minh troops from its territory and to withstand any residual impingement upon its sovereignty by external powers.


title: History of Cambodia

text: Neutrality was the central element of Cambodian foreign policy during the 1950s and 1960s. By the mid-1960s, parts of Cambodia's eastern provinces were serving as bases for North Vietnamese Army and National Liberation Front (NVA/NLF) forces operating against South Vietnam, and the port of Sihanoukville was being used to supply them. As NVA/VC activity grew, the United States and South Vietnam became concerned, and in 1969, the United States began a 14-month-long series of bombing raids targeted at NVA/VC elements, contributing to destabilisation. The bombing campaign took place no further than ten, and later inside the Cambodian border, areas where the Cambodian population had been evicted by the NVA. Prince Sihanouk, fearing that the conflict between communist North Vietnam and South Vietnam might spill over to Cambodia, publicly opposed the idea of a bombing campaign by the United States along the Vietnam–Cambodia border and inside Cambodian territory. However, Peter Rodman claimed, "Prince Sihanouk complained bitterly to us about these North Vietnamese bases in his country and invited us to attack them". In December 1967 "Washington Post" journalist Stanley Karnow was told by Sihanouk that if the US wanted to bomb the Vietnamese communist sanctuaries, he would not object, unless Cambodians were killed. The same message was conveyed to US President Johnson's emissary Chester Bowles in January 1968. So the US had no real motivation to overthrow Sihanouk. However, Prince Sihanouk wanted Cambodia to stay out of the North Vietnam–South Vietnam conflict and was very critical of the United States government and its allies (the South Vietnamese government). Prince Sihanouk, facing internal struggles of his own, due to the rise of the Khmer Rouge, did not want Cambodia to be involved in the conflict. Sihanouk wanted the United States and its allies (South Vietnam) to keep the war away from the Cambodian border. Sihanouk did not allow the United States to use Cambodian air space and airports for military purposes. This upset the United States greatly and contributed to their view that of Prince Sihanouk as a North Vietnamese sympathiser and a thorn on the United States. However, declassified documents indicate that, as late as March 1970, the Nixon administration was hoping to garner "friendly relations" with Sihanouk.


title: History of Cambodia

text: Throughout the 1960s, domestic Cambodian politics became polarised. Opposition to the government grew within the middle class and leftists including Paris-educated leaders like Son Sen, Ieng Sary, and Saloth Sar (later known as Pol Pot), who led an insurgency under the clandestine Communist Party of Kampuchea (CPK). Sihanouk called these insurgents the Khmer Rouge, literally the "Red Khmer". But the 1966 national assembly elections showed a significant swing to the right, and General Lon Nol formed a new government, which lasted until 1967. During 1968 and 1969, the insurgency worsened. However, members of the government and army, who resented Sihanouk's ruling style as well as his tilt away from the United States, did have a motivation to overthrow him.


title: History of Cambodia

text: While visiting Beijing in 1970 Sihanouk was ousted by a military coup led by Prime Minister General Lon Nol and Prince Sisowath Sirik Matak in the early hours of 18 March 1970.


title: History of Cambodia

text: However, as early as 12 March 1970, the CIA Station Chief told Washington that based on communications from Sirik Matak, Lon Nol's cousin, that "the (Cambodian) army was ready for a coup". Lon Nol assumed power after the military coup and immediately allied Cambodia with the United States. Son Ngoc Thanh, an opponent of Pol Pot, announced his support for the new government. On 9 October, the Cambodian monarchy was abolished, and the country was renamed the Khmer Republic. The new regime immediately demanded that the Vietnamese communists leave Cambodia.


title: History of Cambodia

text: Hanoi rejected the new republic's request for the withdrawal of NVA troops. In response, the United States moved to provide material assistance to the new government's armed forces, which were engaged against both CPK insurgents and NVA forces. The North Vietnamese and Viet Cong forces, desperate to retain their sanctuaries and supply lines from North Vietnam, immediately launched armed attacks on the new government. The North Vietnamese quickly overran large parts of eastern Cambodia, reaching to within of Phnom Penh. The North Vietnamese turned the newly won territories over to the Khmer Rouge. The king urged his followers to help in overthrowing this government, hastening the onset of civil war.


title: History of Cambodia

text: In April 1970, US President Richard Nixon announced to the American public that US and South Vietnamese ground forces had entered Cambodia in a campaign aimed at destroying NVA base areas in Cambodia (see Cambodian Incursion). The US had already been bombing Vietnamese positions in Cambodia for well over a year by that point. Although a considerable quantity of equipment was seized or destroyed by US and South Vietnamese forces, containment of North Vietnamese forces proved elusive.


title: History of Cambodia

text: The Khmer Republic's leadership was plagued by disunity among its three principal figures: Lon Nol, Sihanouk's cousin Sirik Matak, and National Assembly leader In Tam. Lon Nol remained in power in part because none of the others were prepared to take his place. In 1972, a constitution was adopted, a parliament elected, and Lon Nol became president. But disunity, the problems of transforming a 30,000-man army into a national combat force of more than 200,000 men, and spreading corruption weakened the civilian administration and army.


title: History of Cambodia

text: The Khmer Rouge insurgency inside Cambodia continued to grow, aided by supplies and military support from North Vietnam. Pol Pot and Ieng Sary asserted their dominance over the Vietnamese-trained communists, many of whom were purged. At the same time, the Khmer Rouge (CPK) forces became stronger and more independent of their Vietnamese patrons. By 1973, the CPK were fighting battles against government forces with little or no North Vietnamese troop support, and they controlled nearly 60% of Cambodia's territory and 25% of its population.


title: History of Cambodia

text: The government made three unsuccessful attempts to enter into negotiations with the insurgents, but by 1974, the CPK was operating openly as divisions, and some of the NVA combat forces had moved into South Vietnam. Lon Nol's control was reduced to small enclaves around the cities and main transportation routes. More than two million refugees from the war lived in Phnom Penh and other cities.


title: History of Cambodia

text: On New Year's Day 1975, Communist troops launched an offensive which, in 117 days of the hardest fighting of the war, caused the collapse of the Khmer Republic. Simultaneous attacks around the perimeter of Phnom Penh pinned down Republican forces, while other CPK units overran fire bases controlling the vital lower Mekong resupply route. A US-funded airlift of ammunition and rice ended when Congress refused additional aid for Cambodia. The Lon Nol government in Phnom Penh surrendered on 17 April 1975, just five days after the US mission evacuated Cambodia.


title: History of Cambodia

text: The relationship between the massive carpet bombing of Cambodia by the United States and the growth of the Khmer Rouge, in terms of recruitment and popular support, has been a matter of interest to historians. Some historians, including Michael Ignatieff, Adam Jones and Greg Grandin, have cited the United States intervention and bombing campaign (spanning 1965–1973) as a significant factor which lead to increased support for the Khmer Rouge among the Cambodian peasantry. According to Ben Kiernan, the Khmer Rouge "would not have won power without U.S. economic and military destabilization of Cambodia. ... It used the bombing's devastation and massacre of civilians as recruitment propaganda and as an excuse for its brutal, radical policies and its purge of moderate communists and Sihanoukists." Pol Pot biographer David P. Chandler writes that the bombing "had the effect the Americans wanted – it broke the Communist encirclement of Phnom Penh", but it also accelerated the collapse of rural society and increased social polarization. Peter Rodman and Michael Lind claimed that the United States intervention saved the Lon Nol regime from collapse in 1970 and 1973. Craig Etcheson acknowledged that U.S. intervention increased recruitment for the Khmer Rouge but disputed that it was a primary cause of the Khmer Rouge victory. William Shawcross wrote that the United States bombing and ground incursion plunged Cambodia into the chaos that Sihanouk had worked for years to avoid.


title: History of Cambodia

text: By 1973, Vietnamese support of the Khmer Rouge had largely disappeared. China "armed and trained" the Khmer Rouge both during the civil war and the years afterward.


title: History of Cambodia

text: Owing to Chinese, U.S., and Western support, the Khmer Rouge-dominated Coalition Government of Democratic Kampuchea (CGDK) held Cambodia's UN seat until 1993, long after the Cold War had ended. China has defended its ties with the Khmer Rouge. Chinese Foreign Ministry spokeswoman Jiang Yu said that "the government of Democratic Kampuchea had a legal seat at the United Nations, and had established broad foreign relations with more than 70 countries".


title: History of Cambodia

text: Immediately after its victory, the CPK ordered the evacuation of all cities and towns, sending the entire urban population into the countryside to work as farmers, as the CPK was trying to reshape society into a model that Pol Pot had conceived.


title: History of Cambodia

text: The new government sought to completely restructure Cambodian society. Remnants of the old society were abolished and religion was suppressed. Agriculture was collectivised, and the surviving part of the industrial base was abandoned or placed under state control. Cambodia had neither a currency nor a banking system.


title: History of Cambodia

text: Democratic Kampuchea's relations with Vietnam and Thailand worsened rapidly as a result of border clashes and ideological differences. While communist, the CPK was fiercely nationalistic, and most of its members who had lived in Vietnam were purged. Democratic Kampuchea established close ties with the People's Republic of China, and the Cambodian-Vietnamese conflict became part of the Sino-Soviet rivalry, with Moscow backing Vietnam. Border clashes worsened when the Democratic Kampuchea military attacked villages in Vietnam. The regime broke off relations with Hanoi in December 1977, protesting Vietnam's alleged attempt to create an Indochina Federation. In mid-1978, Vietnamese forces invaded Cambodia, advancing about before the arrival of the rainy season.


title: History of Cambodia

text: The reasons for Chinese support of the CPK was to prevent a pan-Indochina movement, and maintain Chinese military superiority in the region. The Soviet Union supported a strong Vietnam to maintain a second front against China in case of hostilities and to prevent further Chinese expansion. Since Stalin's death, relations between Mao-controlled China and the Soviet Union had been lukewarm at best. In February to March 1979, China and Vietnam would fight the brief Sino-Vietnamese War over the issue.


title: History of Cambodia

text: In December 1978, Vietnam announced the formation of the Kampuchean United Front for National Salvation (KUFNS) under Heng Samrin, a former DK division commander. It was composed of Khmer Communists who had remained in Vietnam after 1975 and officials from the eastern sector—like Heng Samrin and Hun Sen—who had fled to Vietnam from Cambodia in 1978. In late December 1978, Vietnamese forces launched a full invasion of Cambodia, capturing Phnom Penh on 7 January 1979 and driving the remnants of Democratic Kampuchea's army westward toward Thailand.


title: History of Cambodia

text: Within the CPK, the Paris-educated leadership—Pol Pot, Ieng Sary, Nuon Chea, and Son Sen—were in control. A new constitution in January 1976 established Democratic Kampuchea as a Communist People's Republic, and a 250-member Assembly of the Representatives of the People of Kampuchea (PRA) was selected in March to choose the collective leadership of a State Presidium, the chairman of which became the head of state.


title: History of Cambodia

text: Prince Sihanouk resigned as head of state on 2 April. On 14 April, after its first session, the PRA announced that Khieu Samphan would chair the State Presidium for a 5-year term. It also picked a 15-member cabinet headed by Pol Pot as prime minister. Prince Sihanouk was put under virtual house arrest.


title: History of Cambodia

text: 20,000 people died of exhaustion or disease during the evacuation of Phnom Penh and its aftermath. Many of those forced to evacuate the cities were resettled in newly created villages, which lacked food, agricultural implements, and medical care. Many who lived in cities had lost the skills necessary for survival in an agrarian environment. Thousands starved before the first harvest. Hunger and malnutrition—bordering on starvation—were constant during those years. Most military and civilian leaders of the former regime who failed to disguise their pasts were executed.


title: History of Cambodia

text: Some of the ethnicities in Cambodia, such as the Cham and Vietnamese, suffered specific and targeted and violent persecutions, to the point of some international sources referring to it as the "Cham genocide". Entire families and towns were targeted and attacked with the goal of significantly diminishing their numbers and eventually eliminated them. Life in 'Democratic Kampuchea' was strict and brutal. In many areas of the country people were rounded up and executed for speaking a foreign language, wearing glasses, scavenging for food, absent for government assigned work, and even crying for dead loved ones. Former businessmen and bureaucrats were hunted down and killed along with their entire families; the Khmer Rouge feared that they held beliefs that could lead them to oppose their regime. A few Khmer Rouge loyalists were even killed for failing to find enough 'counter-revolutionaries' to execute.


title: History of Cambodia

text: When Cambodian socialists began to rebel in the eastern zone of Cambodia, Pol Pot ordered his armies to exterminate 1.5 million eastern Cambodians which he branded as "Cambodians with Vietnamese minds" in the area. The purge was done speedily and efficiently as Pol Pot's soldiers quickly killed at least more than 100,000 to 250,000 eastern Cambodians right after deporting them to execution site locations in Central, North and North-Western Zones within a month's time, making it the most bloodiest episode of mass murder under Pol Pot's regime


title: History of Cambodia

text: Religious institutions were not spared by the Khmer Rouge as well, in fact religion was so viciously persecuted to such a terrifying extent that the vast majority of Cambodia's historic architecture, 95% of Cambodia's Buddhist temples, was completely destroyed.


title: History of Cambodia

text: Ben Kiernan estimates that 1.671 million to 1.871 million Cambodians died as a result of Khmer Rouge policy, or between 21% and 24% of Cambodia's 1975 population. A study by French demographer Marek Sliwinski calculated slightly fewer than 2 million unnatural deaths under the Khmer Rouge out of a 1975 Cambodian population of 7.8 million; 33.5% of Cambodian men died under the Khmer Rouge compared to 15.7% of Cambodian women. According to a 2001 academic source, the most widely accepted estimates of excess deaths under the Khmer Rouge range from 1.5 million to 2 million, although figures as low as 1 million and as high as 3 million have been cited; conventionally accepted estimates of deaths due to Khmer Rouge executions range from 500,000 to 1 million, "a third to one half of excess mortality during the period." However, a 2013 academic source (citing research from 2009) indicates that execution may have accounted for as much as 60% of the total, with 23,745 mass graves containing approximately 1.3 million suspected victims of execution. While considerably higher than earlier and more widely accepted estimates of Khmer Rouge executions, the Documentation Center of Cambodia (DC-Cam)'s Craig Etcheson defended such estimates of over one million executions as "plausible, given the nature of the mass grave and DC-Cam's methods, which are more likely to produce an under-count of bodies rather than an over-estimate." Demographer Patrick Heuveline estimated that between 1.17 million and 3.42 million Cambodians died unnatural deaths between 1970 and 1979, with between 150,000 and 300,000 of those deaths occurring during the civil war. Heuveline's central estimate is 2.52 million excess deaths, of which 1.4 million were the direct result of violence. Despite being based on a house-to-house survey of Cambodians, the estimate of 3.3 million deaths promulgated by the Khmer Rouge's successor regime, the People's Republic of Kampuchea (PRK), is generally considered to be an exaggeration; among other methodological errors, the PRK authorities added the estimated number of victims that had been found in the partially-exhumed mass graves to the raw survey results, meaning that some victims would have been double-counted.


title: History of Cambodia

text: An estimated 300,000 Cambodians starved to death between 1979 and 1980, largely as a result of the after-effects of Khmer Rouge policies.


title: History of Cambodia

text: On 10 January 1979, after the Vietnamese army and the KUFNS (Kampuchean United Front for National Salvation) invaded Cambodia and overthrew the Khmer Rouge, the new People's Republic of Kampuchea (PRK) was established with Heng Samrin as head of state. Pol Pot's Khmer Rouge forces retreated rapidly to the jungles near the Thai border. The Khmer Rouge and the PRK began a costly struggle that played into the hands of the larger powers China, the United States and the Soviet Union. The Khmer People's Revolutionary Party's rule gave rise to a guerrilla movement of three major resistance groups – the FUNCINPEC (Front Uni National pour un Cambodge Indépendant, Neutre, Pacifique, et Coopératif), the KPLNF (Khmer People's National Liberation Front) and the PDK (Party of Democratic Kampuchea, the Khmer Rouge under the nominal presidency of Khieu Samphan). "All held dissenting perceptions concerning the purposes and modalities of Cambodia's future". Civil war displaced 600,000 Cambodians, who fled to refugee camps along the border to Thailand and tens of thousands of people were murdered throughout the country.


title: History of Cambodia

text: Peace efforts began in Paris in 1989 under the State of Cambodia, culminating two years later in October 1991 in a comprehensive peace settlement. The United Nations was given a mandate to enforce a ceasefire and deal with refugees and disarmament known as the United Nations Transitional Authority in Cambodia (UNTAC).


title: History of Cambodia

text: On 23 October 1991, the Paris Conference reconvened to sign a comprehensive settlement giving the UN full authority to supervise a cease-fire, repatriate the displaced Khmer along the border with Thailand, disarm and demobilise the factional armies, and prepare the country for free and fair elections. Prince Sihanouk, President of the Supreme National Council of Cambodia (SNC), and other members of the SNC returned to Phnom Penh in November 1991, to begin the resettlement process in Cambodia. The UN Advance Mission for Cambodia (UNAMIC) was deployed at the same time to maintain liaison among the factions and begin demining operations to expedite the repatriation of approximately 370,000 Cambodians from Thailand.


title: History of Cambodia

text: On 16 March 1992, the UN Transitional Authority in Cambodia (UNTAC) arrived in Cambodia to begin implementation of the UN settlement plan and to become operational on 15 March 1992 under Yasushi Akashi, the Special Representative of the U.N. Secretary General. UNTAC grew into a 22,000-strong civilian and military peacekeeping force tasked to ensure the conduct of free and fair elections for a constituent assembly.


title: History of Cambodia

text: Over 4 million Cambodians (about 90% of eligible voters) participated in the May 1993 elections. Pre-election violence and intimidation was widespread, caused by SOC (State of Cambodia – made up largely of former PDK cadre) security forces, mostly against the FUNCINPEC and BLDP parties according to UNTAC. The Khmer Rouge or Party of Democratic Kampuchea (PDK), whose forces were never actually disarmed or demobilized blocked local access to polling places. Prince Ranariddh's (son of Norodom Sihanouk) royalist Funcinpec Party was the top vote recipient with 45.5% of the vote, followed by Hun Sen's Cambodian People's Party and the Buddhist Liberal Democratic Party, respectively. Funcinpec then entered into a coalition with the other parties that had participated in the election. A coalition government resulted between the Cambodian People's Party and FUNCINPEC, with two co-prime ministers – Hun Sen, since 1985 the prime minister in the Communist government, and Norodom Ranariddh.


title: History of Cambodia

text: The parties represented in the 120-member assembly proceeded to draft and approve a new constitution, which was promulgated 24 September 1993. It established a multiparty liberal democracy in the framework of a constitutional monarchy, with the former Prince Sihanouk elevated to King. Prince Ranariddh and Hun Sen became First and Second Prime Ministers, respectively, in the Royal Cambodian Government (RGC). The constitution provides for a wide range of internationally recognised human rights.


title: History of Cambodia

text: Hun Sen and his government have seen much controversy. Hun Sen was a former Khmer Rouge commander who was originally installed by the Vietnamese and, after the Vietnamese left the country, maintains his strong man position by violence and oppression when deemed necessary. In 1997, fearing the growing power of his co-Prime Minister, Prince Norodom Ranariddh, Hun launched a coup, using the army to purge Ranariddh and his supporters. Ranariddh was ousted and fled to Paris while other opponents of Hun Sen were arrested, tortured and some summarily executed.


title: History of Cambodia

text: On 4 October 2004, the Cambodian National Assembly ratified an agreement with the United Nations on the establishment of a tribunal to try senior leaders responsible for the atrocities committed by the Khmer Rouge. International donor countries have pledged a US$43 Million share of the three-year tribunal budget as Cambodia contributes US$13.3 Million. The tribunal has sentenced several senior Khmer Rouge leaders since 2008.


title: History of Cambodia

text: Cambodia is still infested with countless land mines, indiscriminately planted by all warring parties during the decades of war and upheaval.


title: History of Cambodia

text: The Cambodia National Rescue Party was dissolved ahead of the 2018 Cambodian general election and the ruling Cambodian People's Party also enacted tighter curbs on mass media. The CPP won every seat in the National Assembly without a major opposition, effectively solidifying "de facto" one-party rule in the country.


title: History of Cambodia

text: Cambodia’s longtime Prime Minister Hun Sen, one of the world’s longest-serving leaders, has a very firm grip on power. He has been accused of the crackdown on opponents and critics. His Cambodian People’s Party (CPP) has been in power since 1979. In December 2021, Prime Minister Hun Sen announced his support for his son Hun Manet to succeed him after the next election, which is expected to take place in 2023.


title: Egg of Columbus

text: An egg of Columbus or Columbus' egg ( ) refers to a brilliant idea or discovery that seems simple or easy after the fact. The expression refers to an apocryphal story, dating from at least the 16th century, in which it is said that Christopher Columbus, having been told that finding a new trade route was inevitable and no great accomplishment, challenges his critics to make an egg stand on its tip. After his challengers give up, Columbus does it himself by tapping the egg on the table to flatten its tip.


title: Egg of Columbus

text: The story is often alluded to when discussing creativity. The term has also been used as the trade name of a tangram puzzle and several mechanical puzzles. It also shows that anything can be done by anyone with the right set of skills; however, not everyone knows how to do it.


title: Egg of Columbus

text: The Columbus egg story may have originated with Italian historian and traveler Girolamo Benzoni. In his book "History of the New World", published in 1565, he wrote:


title: Egg of Columbus

text: The factual accuracy of this story is called into question by its similarity to another tale published fifteen years earlier (while Benzoni was still travelling in the Americas) by painter and architect Giorgio Vasari. According to Vasari, the young Italian architect Filippo Brunelleschi had designed an unusually large and heavy dome for Santa Maria del Fiore in Florence, Italy. City officials had asked to see his model, but he refused, proposing instead:


title: Egg of Columbus

text: Mary Shelley mentions Columbus's egg in her Introduction to the third edition of "Frankenstein" (1869, p. 10), writing, "In all matters of discovery and invention, even of those that appertain to the imagination, we are continually reminded of the story of Columbus and his egg. Invention consists in the capacity of seizing on the capabilities of a subject, and in the power of moulding and fashioning ideas suggested to it."


title: Egg of Columbus

text: Leo Tolstoy mentions Columbus’s egg in "War and Peace" after Hélène explains to her spiritual guide her reasoning as to why she is not bound by her previous vows of marriage to Pierre after switching religions. "The spiritual guide was astonished at this solution, which had all the simplicity of Columbus’ egg."


title: Egg of Columbus

text: Charles Darwin mentioned the "principle of Columbus & his egg" in his private autobiography (1876-1882, p. 89) when referring to the delayed discovery of his "principle of divergence."


title: Egg of Columbus

text: Westinghouse Electric's Nikola Tesla display at the 1893 Chicago World's Columbian Exposition (celebrating the 400th anniversary of Christopher Columbus's arrival in the New World) used the story in an "Egg of Columbus" exhibit that had the rotating magnetic field in an alternating current induction motor spin a large copper egg until it stood on end.


title: Egg of Columbus

text: F. Scott Fitzgerald refers to Columbus' egg in "The Great Gatsby" when describing the topography of the fictional villages of East Egg and West Egg: "They are not perfect ovalslike the egg in the Columbus story, they are both crushed flat at the contact endbut their physical resemblance must be a source of perpetual wonder to the seagulls that fly overhead."


title: Egg of Columbus

text: Adolf Hitler used the metaphor in "Mein Kampf", saying that " lie around us in hundreds of thousands; but observers like Columbus are rare."


title: Orthodox Church in America

text: The Orthodox Church in America (OCA) is an Eastern Orthodox Christian church based in North America. The OCA is partly recognized as autocephalous and consists of more than 700 parishes, missions, communities, monasteries and institutions in the United States, Canada and Mexico. In 2011, it had an estimated 84,900 members in the United States.


title: Orthodox Church in America

text: The OCA has its origins in a mission established by eight Russian Orthodox monks in Alaska, then part of Russian America, in 1794. This grew into a full diocese of the Russian Orthodox Church after the United States purchased Alaska from Russia in 1867. By the late 19th century, the Russian Orthodox Church had grown in other areas of the United States due to the arrival of immigrants from areas of Eastern and Central Europe, many of them formerly of the Eastern Catholic Churches ("Greek Catholics"), and from the Middle East. These immigrants, regardless of nationality or ethnic background, were united under a single North American diocese of the Russian Orthodox Church.


title: Orthodox Church in America

text: After the Bolshevik Revolution, Patriarch Tikhon of Moscow directed all Russian Orthodox churches outside of Russia to govern themselves autonomously. Orthodox churches in America became a self-governing Russian Orthodox Greek Catholic Church in America in 1924 under the leadership of Metropolitan Platon (Rozhdestvensky), popularly called the Metropolia (from ). The Russian Orthodox Greek Catholic Church in America was granted autocephaly by the Russian Orthodox Church in 1970, and renamed the Orthodox Church in America. Its hierarchs are part of the Assembly of Canonical Orthodox Bishops of the United States of America.


title: Orthodox Church in America

text: Unlike most Orthodox jurisdictions in the United States, the OCA does not have an affinity towards any particular foreign nationality, but most OCA members are ethnically Euro-American, and most OCA clergy are those who are born and raised in the United States. However, the OCA does have other minority ethnic dioceses for Romanian, Bulgarian, and Albanian immigrants. Additionally, as a consequence of history, certain ethnic groups (particularly Ruthenian Americans and Alaska Natives) are disproportionately represented in the OCA compared to the general population. Liturgical and church traditions, such as forms of singing, vestments, iconography, use of Church Slavonic, and architecture broadly reflect those of Russian Orthodoxy.


title: Orthodox Church in America

text: The OCA states that currently the Russian, Bulgarian, Georgian, Polish, Serbian, and Czech and Slovak churches recognize the autocephaly of the OCA. Among the churches that do not recognize it is the Ecumenical Patriarchate of Constantinople, which argues that the Russian Church did not have the authority to grant autocephaly, partly because the Russian Church at the time was considered to be heavily influenced by the Soviet government. The Ecumenical Patriarch also cites Canon 28 of the Council of Chalcedon, which asserted the jurisdiction of the bishop of Constantinople in dioceses located "among the barbarians" (i.e. outside the Roman Empire), as the source of the Ecumenical Patriarchate's authority in the matter. The remaining churches do not recognize the OCA as autocephalous, although they do recognize the self-governing nature of the church. While the subject of political and ecclesiastical dispute, this controversy does not impair the communion between the OCA and the wider Eastern Orthodox Church.


title: Orthodox Church in America

text: According to the April 1970 "Tomos of Autocephaly" granted by the Russian Orthodox Church, the official name of the church is "The Autocephalous Orthodox Church in America". The more comprehensive March 1970 "Agreement of Tomos of Autocephaly", however, states in Article VIII that the legal name of the church was changed to "Orthodox Church in America" (the Russian language does not use the grammatical articles).


title: Orthodox Church in America

text: The first Native Americans to become Orthodox were the Aleuts living in contact with Siberian fur traders in the mid 18th century. They had been baptized mostly by their Orthodox trading partners or during occasional visits by priests serving aboard exploring vessels of the Russian navy. Russian colony in Alaska was established in 1784 by merchant Grigory Shelikhov. Shelikhov's attempt to colonize Kodiak Island was met with resistance by the native population. He returned to Russia and installed Alexandr Baranov as director of the colony. In order to convince the Russian imperial court of the seriousness of his colonial ambitions, Shelikhov recruited volunteers from the Valaam, an environment that appears strikingly similar to the Kodiak archipelago's landscape, and Konevitsa monasteries to travel to the new colony.


title: Orthodox Church in America

text: The volunteers, led by Archimandrite Joasaph Bolotov, departed Saint Petersburg on , and arrived at Kodiak Island on . When they arrived, they were shocked by the harsh treatment of the Kodiak natives at the hands of the Russian settlers and Baranov. They sent reports to Shelikhov detailing the abuse of the local population, but were ignored. In response, however, the Holy Synod created an auxiliary episcopal see in Alaska in 1796, and elected Fr. Joasaph as bishop. Fr. Joasaph and a small party returned to Russia in 1798 for his consecration and to offer first-hand accounts of what they had seen. During their return voyage to the colony in May 1799, their ship sank and all aboard died. In 1800, Baranov placed the remaining monks under house arrest and forbade them to have any further contact with the local population.


title: Orthodox Church in America

text: Despite the lack of leadership, the Orthodox mission in Alaska continued to grow. In 1811, however, the Holy Synod officially closed the episcopal see. It was not until 1823 that the Holy Synod sent instructions for a new priest to travel to Alaska. John Veniaminov of Irkutsk volunteered for the journey, and left Russia in May 1823. He and his family arrived at Unalaska Island on . In 1840, after the death of his wife, Veniaminov accepted monastic tonsure and, taking the name Innocent, ordination as the Bishop of Kamchatka, the Kurile and Aleutian Islands, making him the first ruling bishop of the Alaskan mission since Bishop Joasaph. Bishop Innocent was elevated to archbishop in 1850. For his missionary and scholarly work that had focused on blending indigenous Alaskan languages and cultures with Orthodox tradition, Innocent became a saint of the Orthodox Church in America in 1977, and is referred to as the Enlightener of the Aleuts and Apostle to the Americas.


title: Orthodox Church in America

text: In 1868, the first Orthodox church in the contiguous United States was established in San Francisco, California. Numerous parishes were established across the country throughout the rest of the 19th century. Although these parishes were typically multi-ethnic, most received support from the missionary diocese. In 1872 the diocesan see was relocated from Alaska to the city of San Francisco, California in the United States. The mission itself was instituted as a separate Diocese of Alaska and the Aleutian Islands on June 10, 1870, subsequent to the sale of Alaska to the United States in 1867. In November 1870, the first Orthodox church in New York City was consecrated.


title: Orthodox Church in America

text: Eastern-Rite Catholicism was viewed with suspicion by several Latin-Rite bishops in the United States; some, such as Archbishop John Ireland of Saint Paul, Minnesota, were actually hostile, especially concerning the matter of married clergy. In 1891, Alexis Toth brought a group of 361 Eastern Catholics into Orthodoxy. From then until his death in 1909, Toth brought approximately 20,000 Eastern Catholics from 65 independent communities to Orthodoxy. By 1917, 163 Eastern-Rite Catholic parishes consisting of more than 100,000 faithful had been converted. For his efforts, Toth was glorified as a saint by the OCA in 1994.


title: Orthodox Church in America

text: In recognition of the expansion of the church beyond Alaska, Bishop Tikhon (Belavin) petitioned the Holy Synod to change the diocese's title to the "Diocese of the Aleutians and North America". This was approved in February 1900. He consecrated an auxiliary bishop for Alaska in 1903, and in 1904 he consecrated Raphael Hawaweeny to administer to the Arab parishes. In 1905, Bishop Tikhon relocated the diocesan administration from San Francisco to New York City.


title: Orthodox Church in America

text: In a report to the Holy Synod that year, Bishop Tikhon proposed dramatic changes in the operation of the diocese. Recognizing the needs of the growing multi-ethnic Orthodox community, he recommended reforming the missionary diocese into a self-supporting American diocese, composed of numerous ethnic auxiliary dioceses. His plan called for Russian (New York), Arab (Brooklyn), Serbian (Chicago), and Greek dioceses. Additionally, he called for the formation of a governing council, composed of clergy and laity, which would meet to discuss administrative and canonical issues. On , the first All-American Sobor convened in Mayfield, Pennsylvania. Following Archbishop Tikhon's reassignment to Russia that year, however, few of his reforms were implemented.


title: Orthodox Church in America

text: During this period, education and charity was a focus of the diocese. In 1905, Archbishop Tikhon oversaw the creation of an Orthodox seminary in Minneapolis, Minnesota. St. Platon's Seminary moved from Minneapolis to Tenafly, New Jersey, in 1912 and enrolled 78 students from then until 1923. In 1916, an unaccredited Russian women's college was established in Brooklyn. An immigrant society and orphanage also were established, as well as the first Orthodox monasteries in the United States (Saint Tikhon's Monastery for men in 1905 and Holy Virgin Protection for women in 1915).


title: Orthodox Church in America

text: By 1917, the American diocese was the largest in the Russian Orthodox Church. It had grown from ten parishes in 1890 to more than 350. Most of the funding for the diocese was provided by Russian Church, via the Imperial Missionary Society. The connections between the American diocese and the Russian Church would be severely compromised by the events of that year.


title: Orthodox Church in America

text: The Russian Revolution of 1917 and the subsequent establishment of the Communist Soviet government ushered in a period of repression for the Russian Orthodox Church. Church property was confiscated and, when Patriarch Tikhon resisted, he was imprisoned from April 1922 until June 1923. On , Patriarch Tikhon formally authorized Russian Orthodox bishops to set up temporarily independent organizations, until such time as normal communications with and governance from the patriarchate could be restored.


title: Orthodox Church in America

text: Ethnic groups within the American diocese began to re-align themselves with other national churches. In 1918, a group of Ukrainians in Canada formed the Ukrainian Greek Orthodox Church in Canada, and in 1922, the Greek Orthodox Archdiocese of America was established. In 1926, the Serbs aligned with the Serbian Orthodox Church. As a result of the realignments, Aftimios (Ofiesh) and Platon chartered the American Orthodox Catholic Church in 1927.


title: Orthodox Church in America

text: In Soviet Russia, a splinter group known as the Living Church gained official state recognition in place of the Russian Orthodox Church in 1922. In the United States, a group of Living Church clergy led by John Kedrovsky attempted to depose ruling American hierarch Bishop Alexander (Nemolovsky). Bishop Alexander, in addition to the political and ethnic struggles of his diocese, had also to deal with mounting Church debt as a result of the loss of funds from the Russian Church. He was forced to mortgage Church property to pay creditors and was replaced, in 1922, by Archbishop Platon (Rozhdestvensky), who had previously served as archbishop of the diocese from 1907 to 1914.


title: Orthodox Church in America

text: After Archbishop Platon's return, he was elected Metropolitan of All America and Canada at the third All-American Sobor in November 1922. Soon after, Communist authorities in Russia (in collaboration with the Living Church) attempted to seize church assets in the United States. In response, the fourth All-American Sobor convened in April 1924. During the Sobor, the historic step of declaring the North American diocese to be temporarily self-governing was taken. This was meant to be necessary only until relations with the Russian Church could be normalized, and the justification for the move was the earlier decree by Patriarch Tikhon. The diocese was officially incorporated as the Russian Orthodox Greek Catholic Church of America.


title: Orthodox Church in America

text: Despite the conditions set out by Tikhon's decree for this temporary autonomy not being met, the American diocese of the Russian church declared self-governance in 1924, against the protests of the patriarchate, with which it had communication and which was capable of governance had its American branch been willing. The refusal of the American branch to submit to the patriarchate thus based itself officially on a document whose conditions it had not met. In reality, however, it was a fear of Communism and a belief that the patriarchate had been compromised which fueled the rebellion, paired with a desire on the part of the Metropolia to dissociate itself from the Russian Orthodox Church Outside Russia (ROCOR) of which it had allegedly been part.


title: Orthodox Church in America

text: Despite the declaration of self-governance, Kedrovsky and the Living Church were awarded the church's diocesan cathedral in New York City. To prevent further loss of property, the diocese allowed individual parishes to take ownership of their properties, which made them effectively independent. This, combined with the increasing number of ethnic parishes aligning themselves with other Orthodox jurisdictions (as well as some non-Orthodox), led to a unique situation in Orthodox America whereby multiple jurisdictions overlapped geographically. The remainder of the American Church became known informally as the Metropolia (or under the jurisdiction of the Metropolitan). Following Patriarch Tikhon's death, the Russian Orthodox Church, led by Metropolitan Sergius, began cooperating with the Soviet government. In 1933, the Russian Church declared the Metropolia to be schismatic.


title: Orthodox Church in America

text: A third Russian church, the Synod of Bishops of the Russian Church Abroad (also known as the Karlovtsy Synod and later, the Russian Orthodox Church Outside Russia or ROCOR), formed in 1921. The synod saw itself as representing all Russian Orthodox abroad, including the Metropolia. The Metropolia cooperated with the synod at first but severed relations with them in 1926, citing the synod's increasing claims of authority in America. The synod, for its part, suspended Metropolitan Platon and his clergy. In 1935, an agreement entitled "Temporary Regulations of the Russian Orthodox Church Abroad" was signed that normalized relations between the Metropolia and the ROCOR. The 6th All-American Sobor, held in 1937, affirmed that while the Metropolia remained autonomous, it reported to the ROCOR in matters of faith.


title: Orthodox Church in America

text: The ROCOR, forced to leave Yugoslavia toward the end of World War II, eventually established its base of operations in New York City. In 1946, it was decided at the 7th All-American Sobor that the Metropolia would sever its ties with the ROCOR and attempt to return to the Patriarchate of Moscow. This return was proposed with the stipulation that the Metropolia be allowed to retain its autonomy. When this condition was not met, the Metropolia continued as a self-governing church.


title: Orthodox Church in America

text: Although there were periodic attempts at reconciliation between the Metropolia and the Russian Church over the next few decades, no serious progress was made. During this time, the ethnic character of the Metropolia began to change. Since many Russian immigrants to America aligned themselves with the vocally anti-Communist ROCOR, the Metropolia experienced its growth increasingly through the addition of English-speaking converts. As a result, the ethnic makeup of the Metropolia began to shift away from a purely Slavic one that had included mainly Russians, Ukrainians, Galicians, and Rusyns.


title: Orthodox Church in America

text: Prior to the 13th All-American Sobor in November 1967, a proposal was prepared to change the name of the church from the Russian Orthodox Greek Catholic Church of America to the "Orthodox Church in America". The Council of Bishops, already aware of the proposal, forbade a vote on the matter. After much debate however, a non-binding straw poll was permitted. The result of the poll was decidedly in favor of the name change. As a result, the decision to deal with the matter at another Sobor (to be held in two years) was made.


title: Orthodox Church in America

text: In the early 1960s, the Metropolia resumed communication with the Patriarch of Moscow. In 1968, the Metropolia and the Russian Church communicated informally to resolve long-standing differences. Representatives from the Metropolia sought the right of self-governance, as well as the removal of Russian jurisdiction from all matters concerning the American Church. Official negotiations on the matter began in 1969. On , Patriarch Alexius I and fourteen bishops of the Russian Church's Holy Synod signed the official "Tomos of Autocephaly", which made the newly renamed Orthodox Church in America the fifteenth autocephalous Orthodox Church. The name change, as well as the granting of autocephaly, was officially accepted at the 14th All-American Sobor (also known as the 1st All-American Council in recognition of the Church's new-found independence) in October 1970.


title: Orthodox Church in America

text: The granting of autocephaly by the Moscow Patriarchate was strongly condemned by the Ecumenical Patriarchate of Constantinople as an act that exceeded the former′s authority and violated the canons. Apologists for the OCA's autocephaly claim that the decree did not need the approval of the Ecumenical Patriarchate, as it was an internal matter for the Russian Orthodox Church to decide. Many autocephalous churches, the Russian Church included, were not recognized as such for many years, albeit their autocephaly was granted by the Ecumenical Patriarchate. All canonical Orthodox churches recognize the OCA as canonical and its sacraments as valid, however.


title: Orthodox Church in America

text: The OCA was a member of the Standing Conference of Orthodox Bishops in America (SCOBA), together with the Greek Orthodox Archdiocese of America, the Antiochian Orthodox Christian Archdiocese of North America (AOCA) and the other member jurisdictions. In 2010, SCOBA was dissolved with the creation of the new Assembly of Canonical Orthodox Bishops of North and Central America, which was mandated by Orthodox patriarchates in 2009 at a meeting in Switzerland. Serious consideration has been given recently to a possible merger between the OCA and the AOCA. Both groups share a significant common history, in that a Syrian priest, Raphael Hawaweeny, was sent by the Moscow Patriarchate in the late 19th century as a missionary to Arabic-speaking Orthodox Christians living in North America. Raphael was ordained a bishop in 1904, and his flock eventually became the AOCA. Bishop Raphael was canonized in March 2000 by the OCA as St. Raphael of Brooklyn.


title: Orthodox Church in America

text: In 2005, former treasurer, Protodeacon Eric Wheeler publicly accused the OCA administration of financial misconduct. Wheeler alleged that millions of dollars in donations to the church were improperly used for personal expenses or to cover shortfalls in church accounts.


title: Orthodox Church in America

text: A 32-page report was released on , that addressed the financial scandal and recommended "discipline" for five individuals, including then-primate Metropolitan Herman, his predecessor Metropolitan Theodosius, and two former treasurers as well as a former comptroller. The same report recommended then-primate Metropolitan Herman immediately resign or retire from his post or risk being defrocked.


title: Orthodox Church in America

text: One day after the report was released, Metropolitan Herman resigned from his position as Metropolitan. That November, the OCA elected a new Primate at its 15th Annual All-American Council. Metropolitan Jonah (Paffhausen) was chosen because he had recently been appointed as a bishop (only 11 days prior) and was viewed to not be involved with the previous financial scandal. Metropolitan Jonah immediately took a strong stance against the previous scandal and became a very public metropolitan, seeking to repair damage done by the previous scandal and bring the OCA into the public realm. Metropolitan Jonah also sought to improve relations with non-Orthodox groups and especially sought to repair the relations between the OCA and traditional Anglican groups. He was invited twice to speak at the conference of the Anglican Church in North America, in 2009 and 2012.


title: Orthodox Church in America

text: Less than four years after his election, Metropolitan Jonah was asked by the Holy Synod, in a unanimous decision, to resign from his position. While wary of initially releasing information about the resignation, the Holy Synod felt prompted to release a public statement about his release due to rumors that had spread about their intentions. The statement they released on the official website of the OCA detailed several administrative decisions Metropolitan Jonah had made that the Holy Synod felt put the church and its members at risk. In the statement, the Holy Synod clarified the reason they withheld information initially was to protect the reputation and integrity of Metropolitan Jonah as well as protect anyone involved in the specific decisions made by him.


title: Orthodox Church in America

text: On , an extraordinary All-American Council elected Archbishop Tikhon (Mollard) of Philadelphia and Eastern Pennsylvania as the Metropolitan of All-America and Canada. He was installed on . Metropolitan Tikhon is a convert to the Orthodox faith and a long-time monk of St. Tikhon's Monastery in South Canaan, Pennsylvania.


title: Orthodox Church in America

text: On , in response to Russia's invasion of Ukraine, Metropolitan Tikhon issued a statement saying, in part, 'I ask that the hostilities be ceased immediately and that President Putin put an end to the military operations. As Orthodox Christians, we condemn violence and aggression.' On , he made an urgent appeal for OCA members to contribute to a fund to aid Ukrainian refugees to be administered by the Orthodox Church of Poland. As of , over had been raised.


title: Orthodox Church in America

text: On , Tikhon sent a letter to Patriarch Kirill of Moscow, imploring him to use his influence to help put an end to the war.


title: Orthodox Church in America

text: The exact number of OCA parishioners is debated. According to the 2006 edition of the "Yearbook of American and Canadian Churches", the OCA has 1,064,000 members, an increase of 6.4 percent from 2005. This figure places the OCA as the 24th largest Christian church in the United States, and the second largest Eastern Orthodox church in the country, after the Greek Orthodox Archdiocese of America.


title: Orthodox Church in America

text: In 2000, a study by Alexei D. Krindatch, of the Patriarch Athenagoras Orthodox Institute, presented a substantially lower figure115,100 adherents (baptized Orthodox who attend services on at least an occasional basis and their children) and 39,400 full members (persons older than 18, paying annual Church membership fees). The Greek Orthodox Archdiocese, by comparison, was listed as having 440,000 adherents. In response to the study, an OCA representative stated the church had "around 750,000 adults and children."


title: Orthodox Church in America

text: In 2004, Jonathan Ivanoff stated in a presentation at the OCA's Evangelization Conference that the church's census population in 2004 was 27,169, and that membership from 1990–2000 declined 13 percent. It further stated that the OCA population in the continental United States declined between six and nine percent per year.


title: Orthodox Church in America

text: In 2011, "The Atlas of American Orthodox Christian Churches", published by Holy Cross Orthodox Press and based on research by Alexei Krindatch, was released. It has extensive data on various Orthodox Churches in the United States, including both Eastern Orthodox and Oriental Orthodox groups (as well as groups considered uncanonical by those two groups). The publication is endorsed by the Assembly of Canonical Orthodox Bishops and is being used by various Assembly committees as part of their research and planning. The Atlas lists the United States membership of the OCA as 84,900, 33,800 of which it says are regular church attendees. It lists the OCA as having 551 parishes and 19 monasteries in the United States. It also indicates the states with the heaviest concentration of OCA parishes are, in order: Alaska (with 86), Pennsylvania (with 83), California (with 43) and New York (with 41).


title: Orthodox Church in America

text: The supreme canonical authority of the OCA is the Holy Synod of Bishops, composed of all the church's diocesan bishops. The "ex officio" chairman of the Holy Synod is the metropolitan. The Holy Synod meets twice annually; however, special sessions can be called either by the metropolitan or at the request of at least three diocesan bishops.


title: Orthodox Church in America

text: The primate of the OCA is the metropolitan. He also serves as the bishop of one of the church's dioceses. With the other bishops of the church, the metropolitan is considered the first among equals. His official title is "Metropolitan of All-America and Canada." His role is to manage the welfare of the church, and to act as its representative with other Orthodox Churches, religious organizations, and secular authorities. The metropolitan is elected, when necessary, by the Holy Synod at an All-American Council (a general council of OCA clergy and laity). There are no age or term limits for the metropolitan, and he may retire at any time, but usually does so only for health-related reasons.


title: Orthodox Church in America

text: The diocese is the basic church body that comprises all the parishes of a determined geographical area. It is governed by the Diocesan Bishop, with the assistance of a Diocesan Assembly and a Diocesan Council. The OCA is currently composed of twelve geographic and three ethnic dioceses (Albanian, Bulgarian, and Romanian). The boundaries of the ethnic dioceses overlap those of certain geographic ones. These dioceses are the result of smaller ethnic jurisdictions joining the OCA at some point in its history, usually after having broken from other bodies. Dioceses are established by the Holy Synod whenever needed, and the Synod may also modify the boundaries of an existing diocese.


title: Orthodox Church in America

text: According to the Statute of the Orthodox Church in America, the All-American Council is the "highest legislative and administrative authority within the Church." The Council is composed roughly of the Metropolitan, all bishops, priests, and selected lay delegates. The purpose of the All-American Council is to discuss and vote on Church matters. When necessary, the Council has also elected new metropolitans.


title: Orthodox Church in America

text: The period between All-American Councils is set at three years, although this is not always the case. The first thirteen Councils (held from 1907–1970) are referred to as All-American Sobors, reflecting the American Church's jurisdictional ties to the Russian Orthodox Church. The fourteenth Sobor (held in 1970) is jointly known as the 1st All-American Council, reflecting the autocephalous status of the OCA. The most recent All-American Council (20th) was held in July 2022 in Baltimore, Maryland.


title: Orthodox Church in America

text: The Metropolitan Council is the permanent executive body of the Church's administration. It is tasked with implementing the decisions of the All-American Council, as well as handling the Church's budgetary concerns. The Council is headed by a chairman (the current Metropolitan), and is composed of the OCA's chancellor, secretary, treasurer, and selected clergy and lay delegates. It usually meets twice per year but, in December 2006, a rare joint meeting between the Metropolitan Council and the Holy Synod of Bishops was held.


title: Open-wheel car

text: An open-wheel single-seater (often known as formula car) is a car with the wheels outside the car's main body, and usually having only one seat. Open-wheel cars contrast with street cars, sports cars, stock cars, and touring cars, which have their wheels below the body or inside fenders. Open-wheel cars are built both for road racing and oval track racing. Street-legal open-wheel cars, such as the Ariel Atom, are scarce as they are often impractical for everyday use.


title: Open-wheel car

text: American racecar driver and constructor Ray Harroun was an early pioneer of the concept of a lightweight single-seater, open-wheel "monoposto" racecar. After working as a mechanic in the automotive industry, Harroun began competitive professional racing in 1906, winning the AAA National Championship in 1910. He was then hired by the Marmon Motor Car Company as chief engineer, charged with building a racecar intended to race at the first Indianapolis 500, which he went on to win. He developed a revolutionary concept which would become the originator and forefather of the single-seater (i.e. monoposto) racecar design. Harroun has also been credited by some as pioneering the rear-view mirror which appeared on his 1911 Indianapolis 500 winning car, though he himself claimed he got the idea from seeing a mirror used for a similar purpose on a horse-drawn vehicle in 1904.


title: Open-wheel car

text: Prior to World War II, street automobiles generally had wheels that protruded beyond the vehicle's main body, though they were typically covered with mudguards to protect the car body (and following traffic) from water and mud spray. With the advent of unibody vehicle construction, the desire to maximise interior space, to improve aerodynamics , and aircraft-inspired styling trends of the era, by the end of the 1950s the majority of new road-registerable vehicles had wheels that were under the main body of the car, and thus the open-wheel design became almost exclusively associated with racing vehicles.


title: Open-wheel car

text: Formula One cars have almost exclusively used the open-wheel design throughout the history of the championship. The only notable exception was the "Monza body" variation of the Mercedes-Benz W196 racer of 1954-55, which covered the wheels with bodywork for aerodynamic reasons. Modern Formula One regulations mandate the open-wheel configuration.


title: Open-wheel car

text: A typical open-wheeler has a minimal cockpit, sufficient only to enclose the driver's body, with the head exposed to the air. In the Whelen Modified Tour and other short track modified series, the driver's head is contained in the car. In modern cars, the engine is often located directly behind the driver and drives the rear wheels; except in asphalt modified cars, such as the Whelen Modified Tour, where the engine is in front of the driver. Depending on the rules of the class, many types of open-wheelers have wings at the front and rear of the vehicle, as well as a very low and virtually flat undertray that helps achieve additional aerodynamic downforce pushing the car onto the road. While many other categories of racing cars produce downforce, the top categories of open-wheel racing cars (particularly Formula One and Indycar) produce far more downforce relative to their mass than any other racing category, allowing much higher corner speeds on comparable tracks.


title: Open-wheel car

text: Some major races, such as the Singapore Grand Prix, Monaco Grand Prix (sanctioned by Formula One) and the Long Beach Grand Prix (sanctioned by IndyCar), are held on temporary street circuits. However, most open-wheel races are on dedicated road courses, such as Watkins Glen in the US, Nürburgring in Germany, Spa-Francorchamps in Belgium and Silverstone in Great Britain. In the United States, some top-level open-wheel events are held on ovals, of both short track and superspeedway variety, with an emphasis being placed more on speed and endurance than the maneuverability inherently required by road and street course events. The Whelen Modified Tour is the only opened wheeled race car series endorsed by NASCAR. This series races on most of NASCAR's most famous tracks in the United States. Other asphalt modified series race on short tracks in the United States and Canada, such as Wyoming County International Speedway in New York. The best-attended oval race in the world is the annual Indianapolis 500 (Indy 500) in Speedway, Indiana, sanctioned by IndyCar; in the United States, it is quite common to refer to open-wheel cars as IndyCars, or Champ Cars, because of their recognizable appearance and widespread popularity across America at the Indy 500.


title: Open-wheel car

text: Compared to covered-wheel race cars, open-wheeled cars allow more precise placement of the front wheels on the race course, as the tires are clearly visible to the driver. This allows the maximum potential of the cars to be wrung out during cornering and passing maneuvers. Furthermore, open-wheeled cars are less tolerant of vehicle-to-vehicle contact, which usually results in vehicle damage and retiring, whereas some level of contact is expected in covered-wheel racing, as for example in NASCAR. Open-wheeled drivers must be extremely precise to avoid contact.


title: Open-wheel car

text: Minimum weight requirements tend to be much lower than in categories that more closely resemble street-legal vehicles, such as sports cars, touring cars, and stock cars. For instance, a Formula One must weigh ; the minimum weight for NASCAR is .


title: Open-wheel car

text: Open-wheeled racing is among the fastest in the world. Formula One cars can reach speeds in excess of . At Autodromo Nazionale Monza, Antônio Pizzonia of BMW Williams F1 team recorded a top speed of (over 102 m/s) in the 2004 Italian Grand Prix. Since the end of the V10 era in 2006, speeds like this have not been reached, with contemporary machinery reaching around . It is difficult to give precise figures for the absolute top speeds of Formula One cars, as the cars do not have speedometers as such and the data are not generally released by teams. The 'speed traps' on fast circuits such as Monza give a good indication, but are not necessarily located at the point on the track where the car is travelling at its fastest. BAR Honda team recorded an average top speed of in 2006 at Bonneville Salt Flats with unofficial top speed reaching using their modified BAR 007 Formula One car. Speeds on ovals can range in constant excess of , and at Indianapolis in excess of . In 2000, Gil de Ferran set the one-lap qualifying record of at California Speedway. Even on tight non-oval street circuits such as the Grand Prix of Toronto, open-wheel Indy Cars attain speeds of .


title: Open-wheel car

text: Regardless of top speeds, Formula One open-wheel race cars hold the outright lap record at the circuits which they race due to their combination of top speed, acceleration, and cornering abilities. For example, at the Monza Circuit the fastest lap in the 2021 Grand Prix (Daniel Ricciardo 1:24.812) is more than six seconds per lap faster than the fastest closed-wheel racing car, an LMP1 sports car, and more than 20 seconds per lap faster than the DTM touring car lap record.


title: Open-wheel car

text: Driving an open-wheel car is substantially different from driving a car with fenders. Virtually all Formula One and Indycar drivers spend some time in various open-wheel categories before joining either top series. Open-wheel vehicles, due to their light weight, aerodynamic capabilities, and powerful engines, are often considered the fastest racing vehicles available and among the most challenging to master. Wheel-to-wheel contact is dangerous, particularly when the forward edge of one tire contacts the rear of another tire: since the treads are moving in opposite directions (one upward, one downward) at the point of contact, both wheels rapidly decelerate, torquing the chassis of both cars and often causing one or both vehicles to be suddenly and powerfully flung upwards (the rear car tends to pitch forward, and the front car tends to pitch backward.) An example of this is the 2005 Chicagoland crash of Ryan Briscoe with Alex Barron.


title: Open-wheel car

text: The lower weight of an open-wheel racecar allows for better performance. While the exposure of the wheels to the airstream causes a very high aerodynamic drag at high speeds, it allows improved cooling of the brakes, which is important on road courses with their frequent changes of pace.


title: Open-wheel car

text: In 2018, several single seater series such as Formula One, Formula 2 (with their new Dallara F2 2018 chassis), and Formula E (with their new Spark SRT05e chassis) introduced a protection system to the cockpit called the "halo", a wishbone-shaped frame aimed to deflect debris away from a driver's head. Despite initial criticism, including for the reason of obstructing the driver's vision, it showed some praise in the Formula 2 sprint race in Catalunya when Nirei Fukuzumi spun and had the back of his car land on fellow countryman Tadasuke Makino's halo. In the Formula 1 Belgian Grand Prix, McLaren driver Fernando Alonso was sent airborne after being hit from behind by the Renault of Nico Hülkenberg and struck the halo of Sauber driver Charles Leclerc, thereby saving the Monegasque driver from a visor strike.


title: Open-wheel car

text: In 2019, the newly-formed FIA Formula 3 Championship introduced a halo to their new chassis which was unveiled at the 2018 Abu Dhabi Grand Prix.


title: Open-wheel car

text: In 2020, the Indycar Series adopted a halo combined with an aeroscreen, built by Red Bull Advanced Technologies.


title: Open-wheel car

text: At the start of the 2020 Bahrain Grand Prix, Romain Grosjean collided with Daniil Kvyat in which his car broke in two and burst into flames as it split the barrier. The halo helped prevent Grosjean from possible decapitation while it allowed him to escape from the fire.


title: Cilium

text: The cilium, plural cilia (), is a membrane-bound organelle found on most types of eukaryotic cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projection that extends from the surface of the much larger cell body. Eukaryotic flagella found on sperm cells and many protozoans have a similar structure to motile cilia that enables swimming through liquids; they are longer than cilia and have a different undulating motion.


title: Cilium

text: There are two major classes of cilia: "motile" and "non-motile" cilia, each with a subtype, giving four types in all. A cell will typically have one primary cilium or many motile cilia. The structure of the cilium core called the axoneme determines the cilium class. Most motile cilia have a central pair of single microtubules surrounded by nine pairs of double microtubules called a 9+2 axoneme. Most non-motile cilia have a 9+0 axoneme that lacks the central pair of microtubules. Also lacking are the associated components that enable motility including the outer and inner dynein arms, and radial spokes. Some motile cilia lack the central pair, and some non-motile cilia have the central pair, hence the four types.


title: Cilium

text: Most non-motile cilia are termed "primary cilia" or "sensory cilia" and serve solely as sensory organelles. Most vertebrate cell types possess a single non-motile primary cilium, which functions as a cellular antenna. Olfactory neurons possess a great many non-motile cilia. Non-motile cilia that have a central pair of microtubules are the kinocilia present on hair cells.


title: Cilium

text: Motile cilia are found in large numbers on respiratory epithelial cells – around 200 cilia per cell, where they function in mucociliary clearance, and also have mechanosensory and chemosensory functions. Motile cilia on ependymal cells move the cerebrospinal fluid through the ventricular system of the brain. Motile cilia are also present in the fallopian tubes of female mammals where they function in moving the egg cell from the ovary to the uterus. Motile cilia that lack the central pair of microtubules are the cells of the embryonic primitive node termed "nodal cells" and these nodal cilia are responsible for the left-right asymmetry in bilateral animals.


title: Cilium

text: A cilium is assembled and built from a basal body on the cell surface. From the basal body the ciliary rootlet forms ahead of the transition plate and transition zone where the earlier microtubule triplets change to the microtubule doublets of the axoneme.


title: Cilium

text: The foundation of the cilium is the basal body, a term applied to the mother centriole when it is associated with a cilium. Mammalian basal bodies consist of a barrel of nine triplet microtubules, subdistal appendages and nine strut-like structures, known as distal appendages, which attach the basal body to the membrane at the base of the cilium. Two of each of the basal body's triplet microtubules extend during growth of the axoneme to become the doublet microtubules.


title: Cilium

text: The ciliary rootlet is a cytoskeleton-like structure that originates from the basal body at the proximal end of a cilium. Rootlets are typically 80-100 nm in diameter and contain cross striae distributed at regular intervals of approximately 55-70 nm. A prominent component of the rootlet is rootletin a coiled coil rootlet protein coded for by the "CROCC" gene.


title: Cilium

text: To achieve its distinct composition, the proximal-most region of the cilium consists of a transition zone, also known as the ciliary gate, that controls the entry and exit of proteins to and from the cilium. At the transition zone, Y-shaped structures connect the ciliary membrane to the underlying axoneme. Control of selective entry into cilia may involve a sieve-like function of transition zone. Inherited defects in components of the transition zone cause ciliopathies, such as Joubert syndrome. Transition zone structure and function is conserved across diverse organisms, including vertebrates, "Caenorhabditis elegans", "Drosophila melanogaster" and "Chlamydomonas reinhardtii". In mammals, disruption of the transition zone reduces the ciliary abundance of membrane-associated ciliary proteins, such as those involved in Hedgehog signal transduction, compromising Hedgehog-dependent embryonic development of digit number and central nervous system patterning.


title: Cilium

text: Inside a cilium, is a microtubule-based cytoskeletal core called the axoneme. The axoneme of a primary cilium typically has a ring of nine outer microtubule doublets (called a 9+0 axoneme), and the axoneme of a motile cilium has, in addition to the nine outer doublets, two central microtubule singlets (called a 9+2 axoneme). This is the same axoneme type of the flagellum. The axoneme in a motile cilium acts as a scaffold for the inner and outer dynein arms that move the cilium, and provides tracks for the microtubule motor proteins of kinesin and dynein. The transport of ciliary components is carried out by intraflagellar transport (IFT) which is similar to the axonal transport in a nerve fibre. Transport is bidirectional and cytoskeletal motor proteins kinesin and dynein transport ciliary components along the microtubule tracks; kinesin in an anterograde movement towards the ciliary tip and dynein in a retrograde movement towards the cell body. The cilium has its own ciliary membrane enclosed within the surrounding cell membrane.


title: Cilium

text: In animals, non-motile primary cilia are found on nearly every type of cell, blood cells being a prominent exception. Most cells only possess one, in contrast to cells with motile cilia, an exception being olfactory sensory neurons, where the odorant receptors are located, which each possess about ten cilia. Some cell types, such as retinal photoreceptor cells, possess highly specialized primary cilia.


title: Cilium

text: Although the primary cilium was discovered in 1898, it was largely ignored for a century and considered a vestigial organelle without important function. Recent findings regarding its physiological roles in chemosensation, signal transduction, and cell growth control, have revealed its importance in cell function. Its importance to human biology has been underscored by the discovery of its role in a diverse group of diseases caused by the dysgenesis or dysfunction of cilia, such as polycystic kidney disease, congenital heart disease, mitral valve prolapse, and retinal degeneration, called ciliopathies. The primary cilium is now known to play an important role in the function of many human organs. Primary cilia on pancreatic beta cells regulate their function and energy metabolism. Cilia deletion can lead to islet dysfunction and type 2 diabetes.


title: Cilium

text: Cilia are assembled during the G phase and are disassembled before mitosis occurs. Disassembly of cilia requires the action of aurora kinase A.


title: Cilium

text: The current scientific understanding of primary cilia views them as "sensory cellular antennae that coordinate many cellular signaling pathways, sometimes coupling the signaling to ciliary motility or alternatively to cell division and differentiation."


title: Cilium

text: The cilium is composed of subdomains and enclosed by a plasma membrane continuous with the plasma membrane of the cell. For many cilia, the basal body, where the cilium originates, is located within a membrane invagination called the ciliary pocket. The cilium membrane and the basal body microtubules are connected by distal appendages (also called transition fibers). Vesicles carrying molecules for the cilia dock at the distal appendages. Distal to the transition fibers form a transition zone where entry and exit of molecules is regulated to and from the cilia. Some of the signaling with these cilia occur through ligand binding such as Hedgehog signaling. Other forms of signaling include G protein-coupled receptors including the somatostatin receptor 3 in neurons.


title: Cilium

text: Kinocilia that are found on hair cells in the inner ear are termed as specialized primary cilia, or modified non-motile cilia. They possess the 9+2 axoneme of the motile cilia but lack the inner dynein arms that give movement. They do move passively following the detection of sound, allowed by the outer dynein arms.


title: Cilium

text: Mammals also have motile cilia or secondary cilia that are usually present on a cell's surface in large numbers (multiciliate), and beat in coordinated metachronal waves. Multiciliated cells are found lining the respiratory tract where they function in mucociliary clearance sweeping mucus containing debris away from the lungs. Each cell in the respiratory epithelium has around 200 motile cilia.


title: Cilium

text: In the reproductive tract, smooth muscle contractions help the beating of the cilia in moving the egg cell from the ovary to the uterus.


title: Cilium

text: The functioning of motile cilia is strongly dependent on the maintenance of optimal levels of periciliary fluid bathing the cilia. Epithelial sodium channels (ENaCs) are specifically expressed along the entire length of cilia in the respiratory tract, and Fallopian tube or "oviduct" that apparently serve as sensors to regulate the periciliary fluid.


title: Cilium

text: Motile cilia without the central pair of singlets (9+0) are found in early embryonic development. They are present as nodal cilia on the nodal cells of the primitive node. Nodal cells are responsible for the left-right asymmetry in bilateral animals. While lacking the central apparatus there are dynein arms present that allow the nodal cilia to move in a spinning fashion. The movement creates a current flow of the extraembryonic fluid across the nodal surface in a leftward direction that initiates the left-right asymmetry in the developing embryo.


title: Cilium

text: Motile, multiple, 9+0 cilia are found on the epithelial cells of the choroid plexus. Cilia also can change structure when introduced to hot temperatures and become sharp. They are present in large numbers on each cell and move relatively slowly, making them intermediate between motile and primary cilia. In addition to 9+0 cilia that are mobile, there are also solitary 9+2 cilia that stay immobile found in hair cells.