died 1204, Constantinople
Byzantine emperor.
In 1204 he led a Greek revolt against his coemperors Isaac II and Alexius IV, who had been supported by the Fourth Crusade, and he became the last Greek emperor of united Byzantium before its overthrow and partition by the Crusaders. He imprisoned Alexius IV and demanded the Crusaders leave Constantinople, but they instead besieged the city. He fled to join the fugitive Alexius III (his father-in-law), who, instead of allying with him, had him blinded. Captured by the Crusaders, he was thrown from the top of a column to his death.