Peter II of Aragon

Peter II the Catholic (1178 – 12 September 1213) was the King of Aragon (as Pedro II) and Count of Barcelona (as Pere I) from 1196 to 1213.

He was born in Huesca, the son of Alfonso II of Aragon and Sancha of Castile. In 1205 he acknowledged the feudal supremacy of the papacy and was crowned in Rome by Pope Innocent III, swearing to defend the Catholic faith (hence his surname, "the Catholic"). He was the first king of Aragon to be crowned by the pope.

In the first decade of the thirteenth century he commissioned the Liber feudorum Ceritaniae, an illustrated codex cartulary for the counties of Cerdagne, Conflent, and Roussillon.

On June 15, 1204 he married (as her third husband) Marie of Montpellier, daughter and heiress of William VIII of Montpellier by Eudocia Comnena. She gave him a son, James, but Peter soon discarded her. Marie was popularly venerated as a saint for her piety and marital suffering, but was never canonized; she died in Rome in 1213. He participated in the Battle of Las Navas de Tolosa in 1212 that marked the turning point of Arab domination on the Iberian peninsula.

The Crown of Aragon was widespread in the area that is now southernwestern France, but which at that time was under the control of vassal local princes, such as the Counts of Toulouse. The Cathars or Albingenses rejected the authority and the teachings of the Catholic Church. Innocent called upon Louis IX of France to suppress the Albigenses. Under the leadership of Simon of Montfort a campaign was launched. The Albigensian Crusade, which led to the slaughter of approximately 20,000 men, women and children, Cathar and Catholic alike, essentially destroyed the previously flourishing civilization of Occitania and brought the region firmly under the control of the King of France, and the Capetian dynasty from the north of France.

Peter returned from Las Navas in autumn 1212 to find that Simon de Montfort had conquered Toulouse, exiling Count Raymond VI of Toulouse, who was Peter's brother-in-law and vassal. Peter crossed the Pyrenees and arrived at Muret in September 1213 to confront Montfort's army. He was accompanied by Raymond of Toulouse, who tried to persuade Peter to avoid battle and instead starve out Montfort's forces. This suggestion was rejected.

The Battle of Muret began on September 12, 1213. The Aragonese forces were disorganized and disintegrated under the assault of Montfort's squadrons. Peter himself was caught in the thick of fighting, and died as a result of a foolhardy act of bravado. He was thrown to the ground and killed. The Aragonese forces broke in panic when their king was slain and Montfort's crusaders won a crushing victory.

The nobility of Toulouse, vassals of the Crown of Aragon, were defeated. The conflict culminated in the Treaty of Meaux-Paris in 1229, in which the integration of the Occitan territory into the French crown was agreed upon.

Upon Peter's death, the kingdom passed to his only son by Marie of Montpellier, the future James the Conqueror.