The Albigensian Crusade, which forms the main subject of William of Puylaurens' Chronicle, was a defining episode in the history of France. Launched in 1209 by Pope Innocent III, it was directed against the aristocracy of southern France (especially the Counts of Toulouse) who were accused of protecting heresy, and especially Catharism, a dualist heresy which represented a major threat to the Catholic Church. The Crusade ended in 1229 with the defeat of Count Raymond VII of Toulouse. It was followed in the 1230s by the establishment of the Papal Inquisition against heresy. The long-term...