Carcassonne became famous in its role in the Albigensian Crusades, when the city was a stronghold of Occitan Cathars. In August 1209 the crusading army of Simon de Montfort forced its citizens to surrender. Raymond-Roger de Trencavel was imprisoned whilst negotiating his city’s surrender, held in his own dungeon and allowed to die. Montfort was appointed the new viscount. He added to the fortifications. Carcassonne became a border citadel between France and the kingdom of Aragon (Spain).
An interesting postscript: Author Kate Mosse wrote the novel “Labyrinth”, which takes
place in modern-day France and in Medieval Carcassonne, and features both Raymond-Roger
de Trencavel and Simon de Montfort. The story involves the search for the Holy Grail, and is a
fascinating read. Ridley and Tony Scott are currently adapting this novel for television, with Tom Felton as Trencavel and John Lynch as Montfort.