Facts and Events
Guy joined his father on the Albigensian Crusade while still quite young. Late in 1216, he married Petronilla, the heiress to Bigorre and Marsan through her mother Stephanie, and a daughter of Bernard IV of Comminges.
He fought at his father's side at the siege of Toulouse in 1218, but his father died: crushed by the projectile of a siege engine. Amaury VI de Montfort inherited his father's command, but not his strategic vision. The Occitan lords rebelled against him and Guy was killed in a conflict at Castelnaudary in 1220, either on 4 April or in July.
Guy left a daughter, Alice, who succeeded Petronilla. He also left a daughter named Pernelle, who married Raoul de la Roche-Tesson.