The road to Hungary and Austria lay open, but Suleiman turned his attention instead to the Eastern Mediterranean island of Rhodes, the home base of the Knights Hospitaller. Suleiman built a large fortification, Marmaris Castle, that served as a base for the Ottoman Navy. Following the five-month Siege of Rhodes (1522), Rhodes capitulated and Suleiman allowed the Knights of Rhodes to depart.[17] The conquest of the island cost the Ottomans 50,000[18][19] to 60,000[19] dead from battle and sickness (Christian claims went as high as 64,000 Ottoman battle deaths and 50,000 disease deaths).[19]
Its capture was vital in removing the Hungarians and Croats who, following the defeats of the Albanians, Bosniaks, Bulgarians, Byzantines and the Serbs, remained the only formidable force who could block further Ottoman gains in Europe. Suleiman encircled Belgrade and began a series of heavy bombardments from an island in the Danube. Belgrade, with a garrison of only 700 men, and receiving no aid from Hungary, fell in August 1521.[16]: 49
Suleiman during the siege of Rhodes in 1522 Upon succeeding his father, Suleiman began a series of military conquests, eventually leading to a revolt led by the Ottoman-appointed governor of Damascus in 1521. Suleiman soon made preparations for the conquest of Belgrade from the Kingdom of Hungary—something his great-grandfather Mehmed II had failed to achieve because of John Hunyadi's strong defense in the region.
Accession Upon the death of his father, Selim I (r. 1512–1520), Suleiman entered Constantinople and ascended to the throne as the tenth Ottoman Sultan. An early description of Suleiman, a few weeks following his accession, was provided by the Venetian envoy Bartolomeo Contarini: The sultan is only twenty-five years [actually 26] old, tall and slender but tough, with a thin and bony face. Facial hair is evident but only barely. The sultan appears friendly and in good humor. Rumor has it that Suleiman is aptly named, enjoys reading, is knowledgeable and shows good judgment."[14]: 2
Suleiman was born in Trabzon on the southern coast of the Black Sea to Şehzade Selim (later Selim I), probably on 6 November 1494, although this date is not known with absolute certainty or evidence.[13] His mother was Hafsa Sultan, a convert to Islam of unknown origins, who died in 1534.[14]: 9 At the age of seven, Suleiman began studies of science, history, literature, theology and military tactics in the schools of the imperial Topkapı Palace in Constantinople. As a young man, he befriended Pargalı Ibrahim, a slave who later became one of his most trusted advisers (but who was later executed on Suleiman's orders)[15] At age seventeen, he was appointed as the governor of first Kaffa (Theodosia), then Manisa,with a brief tenure at Edirne.