B orn in 1185, he is the son of Pierre-Roger le Vieux, the Lord of Mirepoix. Vassal of the count of Foix from 1223, he signs numerous charters as witness, notably in 1226 when the counts of Foix and of Toulouse become allied against the crusade of Louis VII. Mirepoix having been given to Guy de Lévis in 1229, Pierre Roger take refuge with Montségur of whom he is a co-Lord with his German cousin Raimond de Péreille . He appears with the count of Foix until 1236 but, condemned by the Inquisition in 1237 for the Cathar sympathies (they are six Parfaits in his family) he becomes an outlaw. In 1240, he participates in Raimond Trencavel's attempt to resume Carcassonne. Pushed away he is nearly captured by the royal army. In May, 1242, he steers the massacre of the inquisitors to Avignonet. This action provokes an immense enjoyment in all South of France which stirs up. But the king reacts and, in two months, cities and castles are lent oath to the king, with the exception of Montségur. Pierre-Roger defenses the citadel ; the seat begins in December, 1243. On March 2, 1244, Pierre-Roger tries to negotiate: he obtains safe life for all the laymen, amnesty for the Avignonet's affair as well as an armistice until March 16. After the seat, Pierre - Roger settles down over Foix, to Montgaillard. By 1260, it he is still known as Lord " faidit " then disappears completely.