Sultan of the Ottoman Empire (1444-1446 and 1451-1481).
Mehmed II first came to the throne aged twelve on the abdication of his father Murad II in 1444. He was immediately faced by a severe military challenge from John Hunyadi, the voivod of Translyvania, and King Vladislav I of Hungary. His father returned from retirement to lead the Ottoman troops who defeated Hunyadi and Vladislav at the battle of Varna in 1444. Mehmed continued to rule, with considerable difficulty, until he was eventually deposed as the result of a janissary revolt in 1446 and Murad was restored.
On the death of Murad II in 1451, Mehmed returned once more to the throne. In 1453 he took the city of Constantinople (mod. Istanbul, Turkey), a conquest of great symbolic value, which firmly established the Ottoman state as an empire to be reckoned with. The fall of the Byzantine Empire caused deep consternation in Europe, many fearing that the Ottomans would appear in Rome itself and that the whole of Christendom was in the deadliest danger. The contemporary Nicola Sagundino declared that Mehmed’s every thought and action were directed toward the extermination of the Christians. There were many calls for a crusade, in particular by the Hospitallers, who urged the pope to coordinate action against the Ottomans, and called for Christian unity in the face of this great danger.
During Mehmed’s reign the frontiers of the Ottoman state were further extended, both in the east and the west. In 1458 he took Athens, the Morea in 1460, and Negroponte (Euboia) in 1470, and he laid siege to Rhodes in 1480. Serbia fell in 1459 and Bosnia in 1464. In Anatolia, Mehmed disposed of both Uzun Hasan, the Akkoyunlu ruler, defeated in 1473, and the Turkish state of Karaman, which had for so long been a rival to Ottoman power in central Anatolia and which was conquered in 1474. Mehmed extended Ottoman control northward across the Black Sea. The Crimea became a vassal state, and the Genoese trading colony in Caffa (mod. Feodosiya, Ukraine) fell to the Ottomans in 1475. The extent of Ottoman advance was made very explicit for the European powers when Ottoman troops landed in Italy and took Otranto in 1480. Mehmed encouraged commercial activity and paid great attention to cultivating his relations with the Western trading states. Often regarded as cruel (Niccolo Tignosi described him as a new Caligula), Mehmed was also described by contemporaries as a shrewd administrator, temperate and austere by nature, and a man of learning, with a particular interest in ancient history.