Mahmud I (mämōdˈ, mäˈmōd) [key], 1696–1754, Ottoman sultan (1730–54), son of Mustafa II, nephew and successor of Ahmed III. A revolt of the Janissaries put him on the throne of the Ottoman Empire (Turkey). Affairs of state were largely in the capable hands of the Nubian agha [officer], Beshir (1653–1746), who was the power behind a number of successive grand viziers (chief executive officers). During Mahmud's reign, the Ottoman Empire was involved in wars with Persia. War with Russia broke out in 1736. Holy Roman Emperor Charles VI entered the war in 1737 on the Russian side, but by the separate peace of Belgrade (1739) he restored N Serbia to Turkey. Mahmud was succeeded by his brother, Osman III.