Murad IV, 1612?–1640, Ottoman sultan (1623–40), nephew and successor of Mustafa I. He recovered (1638) Baghdad, which Shah Abbas I of Persia had seized. On his victory he sent an order to murder his brother Beyazid. Murad possessed prodigious strength and ruled with ruthless severity. The Greek patriarch Cyril Lucaris was another of his victims. Murad was succeeded by his brother Ibrahim (reigned 1640–48) and Ibrahim's son Muhammad IV.