شيخ الإسلام
After 1453, Mehmed the Conqueror (1432–1481) had established eight madrasas in former Byzantine church buildings, and later founded the "sahn-ı şeman" or "Eight courtyards madrasa", adjacent to the Fatih mosque, where he brought together the most distinguished Islamic law scholars of his territory. In his 2015 study on the "second formation of Islamic law", Burak has shown in detail how the Ottoman state gradually imposed upon the traditional ulama a hierarchy of "official imperial scholars", appointed and paid by the central government. From the conquest of the Mamluk Sultanate of Cairo in 1517 onwards, the Ottoman ulama set up their own interpretation of the Sunni Hanafi doctrine which then served as the official religious doctrine of the empire. The formal acknowledgment by decree of the sultan became a prerequisite to issue fatwas. In the 17th century, the annalist al-Hamawi used the expression "sultanic mufti" "(al-ifta' al-sultani)" to delineate the difference between the officially appointed religious leaders and those who had followed the traditional way of education. Other authors at that time called the Ottoman law scholars "Hanafi of Rūm [i.e., the Ottoman Empire]" "(Rūmi ḫānāfi)", "Scholars of Rūm" "(ʿulamā'-ı rūm)" or "Scholars of the Ottoman Empire" "(ʿulamā' al-dawla al-ʿUthmaniyyā)". The Shaykh al-Islām "()" in Istanbul became the highest-ranking Islamic scholar within, and head of the ulama throughout the empire.