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.
Rise of the Ottoman Empire
In 1938 the Austrian historian Paul Wittek published an influential work entitled "The Rise of the Ottoman Empire", in which he put forth the argument that the early Ottoman state was constructed upon an ideology of Islamic holy war against non-Muslims. Such a war was known as "gaza", and a warrior fighting in it was called a "gazi". Wittek's formulation, subsequently known as the "Gaza Thesis," was influential for much of the twentieth century, and led historians to portray the early Ottomans as zealous religious warriors dedicated to the spread of Islam. Beginning in the 1980s, historians increasingly began to criticize Wittek's thesis. Scholars now recognize that the terms "gaza" and "gazi" did not have strictly religious connotations for the early Ottomans, and were often used in a secular sense to simply refer to raids. Additionally, the early Ottomans were neither strict orthodox Muslims nor were they unwilling to cooperate with non-Muslims, and several of the companions of the first Ottoman rulers were either non-Muslims or recent converts. The idea of holy war existed during the fourteenth century, but it was only one out of many factors influencing Ottoman behavior. It was only later, in the fifteenth century, that Ottoman writers retroactively began to portray the early Ottomans as zealous Islamic warriors, in order to provide a noble origin for their dynasty which had by then constructed an intercontinental Islamic empire.