At its height, the Ottoman Empire spanned an area from Hungary in the north to Yemen in the south and from Algeria in the west to Iraq in the east.

The partitioning of the Empire by the victorious Allies and the ensuing Turkish War of Independence led to the abolition of the sultanate in 1922 and the birth of the modern Republic of Turkey in 1922.

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.

[7] 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.

After the conquest of Constantinople in 1453 by Mehmed II, Ottoman sultans came to regard themselves as the successors of the Roman Empire, hence their occasional use of the titles caesar (قیصر qayser) of Rûm, and emperor,[6][8][9] as well as the caliph of Islam.

[b] Newly enthroned Ottoman rulers were girded with the Sword of Osman, an important ceremony that served as the equivalent of European monarchs' coronation.

[16] In 1617, the law of succession changed from survival of the fittest to a system based on agnatic seniority (اکبریت ekberiyet), whereby the throne went to the oldest male of the family.