Territorial evolution of the Ottoman Empire
Suleiman I ( "Süleymān", ; almost always "Kanuni Sultan Süleyman") (6 November 1494  – 5/6/7 September 1566), was the tenth and longest-reigning Sultan of the Ottoman Empire, from 1520 to his death in 1566. Suleiman became a prominent monarch of 16th century Europe. Suleiman personally led Ottoman armies to conquer the Christian strongholds of Belgrade, Rhodes, and most of Hungary. In 1541 he annexed central Hungary while Transylvania became an Ottoman vassal. However rest of the Kingdom of Hungary including western and northern (Upper) Hungary and Croatia still were Habsburgs possessions. Suleiman also conquered Iraq in his conflict with the Safavid dynasty. Under his rule, the Ottoman fleet dominated the seas from the Mediterranean to the Red Sea and the Persian Gulf.
Selim I
Selim's conquest of the Middle Eastern heartlands of the Muslim world, and particularly his assumption of the role of guardian of the pilgrimage routes to Mecca and Medina, established the Ottoman Empire as the most prestigious of all Sunni Muslim states. His conquests dramatically shifted the empire's geographical and cultural center of gravity away from the Balkans and toward the Middle East. By the eighteenth century, Selim's conquest of the Mamluk Sultanate had come to be romanticized as the moment when the Ottomans seized leadership over the rest of the Muslim world, and consequently Selim is popularly remembered as the first legitimate Ottoman Caliph, although stories of an official transfer of the caliphal office from the Abbasids to the Ottomans were a later invention.