Guy de Montfort was the Count of Bigorre from 6 November 1216 to 1220 in right of his wife, Petronilla. He was a son of Simon IV de Montfort and Alice of Montmorency. 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. Guy left a daughter, Alice, who succeeded Petronilla. He also left a daughter named Pernelle, who married Raoul de la Roche-Tesson.[citation needed]