Known in lay and religious life for his intelligence, piety, and devotion. Archdeacon of Maguelone in 1199. Cistercian monk at Fontfroide c.1202. Papal legate and inquisitor in 1203 under Pope Innocent III. Assigned to work with the heretic Albigensians, to bring them back to the church. He embarked on a great evangelization campaign through southern France; Saint Dominic de Guzman worked in this effort. Martyred by Albigensians, probably with the support of Count Raymond VI of Toulouse who hoped to use the Albigensian crisis to increase his political power. Peter’s murder sparked the Albigensian Crusade against the heretics in southern France.
- near Montpellier, France
May God forgive thee, brother, as I fully forgive thee. -Blessed Peter’s dying words
- “Blessed Peter of Castelnau“. CatholicSaints.Info. 18 January 2017. Web. 24 March 2017. <>