He was a vassal of viscount Raymond Roger Trencavel, and was present with him during the siege of the castrum of Carcassonne in early stages of the Albigensian Crusade in 1209.
Allegedly, Pierre-Roger advised Trencavel to remain in the castrum rather than meet the crusader army in the open field, because he was outnumbered.
He successfully defended his castles against Simon de Montfort, 5th Earl of Leicester, but months later capitulated without military actions.
Dominique Paladilhe, Simon de Montfort, Librairie Académique Perrin, 1988 (réimpr.
1997), p. 324 (ISBN 2-262-01291-1) Georges Bordonove, La Tragédie Cathare, Paris, Pygmalion – Gérard Watelet, coll.