Peter II, 1174–1213, king of Aragón (1196–1213) and count of Barcelona, son and successor of Alfonso II. He had himself crowned (1204) at Rome by Pope Innocent III, whom he accepted as overlord of Aragón and Catalonia. In 1212 he helped Alfonso VIII of Castile defeat the Moors at Las Navas de Tolosa. In 1213, Peter went to the assistance of his brother-in-law Raymond VI of Toulouse and his own vassals in France against Simon de Montfort, leader of the Albigensian Crusade. He was slain in the battle of Muret, which marked the end of Aragonese hegemony in S France. His son James I succeeded him.