Towards the end of the wars against the Cathars this was one of their last sanctuaries, providing support for Montségur. The seigneurs of Usson, Bernard d'Alion, lord of the Château de Montaillou, and his brother Arnaud d'Usson sent arms and supplies to their besieged comrades there. On 15 March 1244, the day before 225 Cathar "parfaits" were burned alive at Montségur, four other "parfaits" left the castle there for Usson, where the Cathar treasure had been evacuated a few months earlier. This mystery has fed a number of theories about the equally mysterious treasure supposedly found at Rennes-le-Château in the 19th century.