Ahmed III, 1673–1736, Ottoman sultan (1703–30), brother and successor of Mustafa II to the throne of the Ottoman Empire (Turkey). He gave asylum to Charles XII of Sweden and to Mazepa after Peter the Great of Russia had defeated (1709) them at Poltava. Charles's advice helped to bring about war between Turkey and Russia (1710–11). By the Treaty of the Pruth (1711), Turkey recovered Azov and the surrounding territory from Russia. Ahmed seized (1715) the Peloponnesus and the Ionian Isles (except Corfu) from Venice, but he was defeated by the Austrians under Prince Eugene of Savoy in 1716–18. By the Treaty of Passarowitz (1718), Banat, Lesser Walachia, and N Serbia, including Belgrade, were lost to the Hapsburg emperor. Ahmed's grand vizier (chief executive officer) after 1718 was Ibrahim, who encouraged learning by establishing several notable libraries and favored the rise of Greek Phanariots (see under Phanar) to high offices. The sultan and his minister were overthrown by the Janissaries, who were jealous of the new aristocracy. Ahmed's nephew Mahmud I became sultan, and Ahmed died in prison.