Michael II (Michael the Stammerer), d. 829, Byzantine emperor (820–29). A native of Phrygia, he fought with Emperor Leo V, whom he had helped gain the throne. Leo had him arrested for heading a conspiracy, but the plotters murdered Leo and raised Michael to the throne. In the religious controversy, Michael tolerated both orthodoxy and iconoclasm but personally favored iconoclasm. He lost (825) Crete to the Arabs, who began (827) the invasion of Sicily. He was succeeded by his son Theophilus and by (842) his grandson Michael III.