The name of four Byzantine emperors: A. I., Comnenus, killed his ward, Alexis II., usurped the throne, and was put to death, 1183; A. II., lived to see the empire devastated by the Turks (1282-1328); A. III., grandson of the preceding, dethroned him, fought stoutly against the Turks without staying their advances (1328-1341); A. IV. dethroned his father, Soter V., and was immediately stripped of his possessions himself (1377-1378).