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.
Islam in Turkey
The secularization of Turkey started in the society during the last years of the Ottoman Empire and it was the most prominent and most controversial feature of Atatürk's reforms. Under his leadership, the caliphate—the supreme politico-religious office of Sunni Islam, and symbol of the sultan's claim to world leadership of all Muslims—was abolished. The secular power of the religious authorities and functionaries was reduced and eventually eliminated. The religious foundations were nationalized, and religious education was restricted and for a time prohibited. The influential and popular mystical orders of the dervish brotherhoods (Tariqa) also were suppressed.