1911 Encyclopædia Britannica/Pierre de Castelnau

PIERRE DE CASTELNAU (d. 1208), French ecclesiastic, was born in the diocese of Montpellier. In 1199 he was archdeacon of Maguelonne, and was appointed by Pope Innocent III. as one of the legates for the suppression of heresy in Languedoc. In 1202, when a monk in the Cistercian abbey of Fontfroide, Narbonne, he was designated to similar work, first in Toulouse, and afterwards at Viviers and Montpellier. In 1207 he was in the Rhone valley and in Provence, where he became involved in the strife between the count of Baux and Raymond, count of Toulouse, by one of whose agents he was assassinated on the 15th of January 1208. He was beatified in the year of his death by Pope Innocent III.

See De la Bouillerie, Le Bienheureux Pierre de Castelnau et les Albigeois au XIII. siècle (Paris, 1866).