Martin IV, d. 1285, pope (1281–85), a Frenchman named Simon de Brie; successor of Nicholas III. He was chancellor under Louis IX of France and was created cardinal by Urban IV. He was thus a supporter of the Angevin dynasty in S Italy and Sicily. In supporting the design of Charles of Anjou (see Charles I) to restore the Latin Empire of Constantinople, and in his excommunication of Byzantine Emperor Michael VIII, Martin sacrificed (1281) the recent union of East and West made at Lyons (1274). After the revolt known as the Sicilian Vespers he turned all his powers against Peter III of Aragón. Martin adopted the title Martin IV because it was believed then that the two popes named Marinus were named Martin. He is actually only the second pope named Martin. He was succeeded by Honorius IV.