Avidius Cassius, Gaius  ( born , Syria—died c. AD 130 , Egyptaccording to Hornblower, Simon and Spawforth, Antony, (eds.), Oxford Classical Dictionary, 3rd ed., Clarendon Press, Oxford, 1996. p. 226"was born in Egypt presumably AD 130, while his father was there with Hadrian"—died July 175 )  usurping ok hb 5/18/07usurping Roman emperor for three months in AD 175.

The son of a high civil servant of the emperor Hadrian (ruled 117–138), Avidius directed operations under the command of the emperor Verus in Rome’s war against the Parthians (161–165). In 164–165 Avidius advanced into Mesopotamia and then sacked Ctesiphon, Parthia’s capital, and Seleucia—both located in present-day central Iraq. Soon he was made commander of all Roman military forces in the Eastern provinces, and in 172 161–166). OCD, p.223 says 162 see note http://books.google.com/books?id=eFnRw51m2nMC&pg=PA93&lpg=PA93&dq=163+avidius+mesopotamia&source=web&ots=9GOhbFw49w&sig=ZktJkBxzu3qEThtUfuihuA0RPNo"In 161 Vologaeses of Parthia seized Armenia and overcame two Roman armies. Verus arrived in Antioch in 163 but it was his generals, Statilius Priscus, who overtook Armenia in 163 and Avidius Cassius who captured Seleucia and Ctesiphon in 165, and made Mesopotamia a Roman protectorate."By 165 Avidius had advanced into Mesopotamia, sacked Seleucia, and destroyed the royal palace in the capital, Ctesiphon. (Both cities are on the Tigris River south of modern Baghdad.) In 166 Marcus Aurelius (reigned 161–180) made him governor of Syria; by 172, when he suppressed an agrarian revolt in Egypt, he was supreme commander of the Roman forces in the East. In April spring 175 Avidius suddenly proclaimed had himself emperor. He had apparently acted declared emperor by his troops, perhaps after hearing a false rumour report of the death of the emperor Marcus Aurelius (ruled 161–180), who was campaigning on the Danube. Marcus set out for the East, but before the two rivals could confront each other, he did not have to complete the trip; Avidius was assassinated by one of his own soldiers, and his head was brought to Marcus.