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.
Ottoman dynasty
The first Ottoman ruler to actually claim the title of "Sultan" was Murad I, who ruled from 1362 to 1389. The holder of the title Sultan (سلطان in Arabic) was in Arabic-Islamic dynasties originally the power behind the throne of the Caliph in Bagdad and it was later used for various independent Muslim Monarchs. This title was senior to and more prestigious than that of Amir; it was not comparable to the title of Malik 'King', a secular title not yet common among Muslim rulers, or the Persian title of Shah, which was used mostly among Persian or Iranian related rulers.