Battle of Muret, (September 12, 1213), military engagement of the Albigensian Crusade. It played a significant role in ending Aragonese interests in territories north of the Pyrenees and in bringing the province of Languedoc under the influence of the French crown.
French Crusaders led by Simon de Montfort, seeking to destroy the Cathar religious sect based in southern France, were opposed by Count Raymond VI of Toulouse. Simon’s forces had already conquered the viscounty of Béziers-Carcassonne in 1209 but had been repelled in an assault on Toulouse, which remained loyal to Raymond VI. Raymond and the bourgeois of Toulouse invoked the aid of King Peter II of Aragon. Peter, who had not given up his predecessors’ design of increasing Aragon’s feudal power by acquiring vassals north of the Pyrenees, finally responded to the appeal.
Though their combined forces were considerably superior to Simon’s, misunderstanding between Peter and Raymond led to their defeat. Coming westward out of Muret, Simon attacked Peter’s camp, and Peter’s death in that engagement gave the signal for a general flight. The militia of Toulouse, assailed unexpectedly in the camp, suffered heavy losses. Subsequent negotiations resulted in the submission of Toulouse (1214–15), but Raymond was able to reclaim the town in 1217.