how did the sultan ruled the ottoman empire
The Ottoman Empire was an absolute monarchy during much of its existence. By the second half of the fifteenth century, the sultan sat at the apex of a hierarchical system and acted in political, military, judicial, social, and religious capacities under a variety of titles. He was theoretically responsible only to God and God's law (the Islamic شریعت ‎ şeriat, known in Arabic as شريعة sharia), of which he was the chief executor. His heavenly mandate was reflected in Islamic titles such as "shadow of God on Earth" (ظل الله في العالم ‎ ẓıll Allāh fī'l-ʿalem) and "caliph of the face of the earth" (خلیفه روی زمین ‎ Ḫalife-i rū-yi zemīn). All offices were filled by his authority, and every law was issued by him in the form of a decree called firman (فرمان ‎). He was the supreme military commander and had the official title to all land. Osman (died 1323 / 4) son of Ertuğrul was the first ruler of the Ottoman state, which during his reign constituted a small principality (beylik) in the region of Bithynia on the frontier of the Byzantine Empire.