Islam in the Ottoman Empire
Islam was the official religion of the Ottoman Empire. The highest position in Islam, "caliphate", was claimed by the sultan, after the defeat of the Mamluks which was established as Ottoman Caliphate. The Sultan was to be a devout Muslim and was given the literal authority of the Caliph. Additionally, Sunni clerics had tremendous influence over government and their authority was central to the regulation of the economy. Despite all this, the Sultan also had a right to decree, enforcing a code called Kanun (law) in Turkish. Additionally, there was a supreme clerical position called the Sheykhulislam ("Sheykh of Islam" in Arabic). Minorities, particularly Christians and Jews but also some others, were mandated to pay the jizya, the poll tax as mandated by traditional Islam.
Mehmet Fuat Köprülü
In 1933, Fuat Köprülü became a professor ordinarius, a title denoting a professor of the highest rank in Turkey. In 1935, he delivered a series of influential lectures at the University of Paris (Sorbonne) on the origins of the Ottoman Empire. Fuat Köprülü argued that ethnic Turks formed the Ottoman Empire using Seljuk and Ilhanid administrative traditions, and he discredited the prevailing view among Western scholars that the Ottoman Empire was formed by a race of predominantly Greek and Slavic converts to Islam.