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
In 1922 the new nationalist regime abolished the Ottoman sultanate, and in 1924 it abolished the caliphate, the religious office that Ottoman sultans had held for four centuries. Thus, for the first time in Islamic history, no ruler claimed spiritual leadership of Islam.
Atatürk and his associates not only abolished certain religious practices and institutions but also questioned the value of religion, preferring to place their trust in science. They regarded organized religion as an anachronism and contrasted it unfavorably with "civilization," which to them meant a rationalist, secular culture. Establishment of secularism in Turkey was not, as it had been in the West, a gradual process of separation of church and state. In the Ottoman Empire, all spheres of life, at least theoretically, had been subject to traditional religious law, and Sunni religious organizations had been part of the state structure. However, usually state had authority over the clergy and religious law, even at the Ottoman period (e.g.many Sultans are known to change Şeyhülislams, who do not approve state politics). When the reformers of the early 1920s opted for a secular state, they removed religion from the sphere of public policy and restricted it exclusively to that of personal morals, behavior, and faith. Although private observance of religious rituals could continue, religion and religious organization were excluded from public life.