Joint rule with Theophilus (his son), from 12 May 821 (or 1 June 822).
Michael II started his career as a humble soldier. Leo V's assassination while trying to impose iconoclasm probably taught Michael a lesson, as he chose to remain religiously neutral. With Bulgarian help, he defeated the usurper Thomas, who with his Arab allies even besieged Constantinople for one year. Even after the rebellion was crushed, the Arabs still occupied Crete and initiated an invasion of Sicily.