Roger Bernard III of Foix-Castelbon
Roger Bernard III of Foix-Castelbon (1310–1350) was the younger son of Count Gaston I of Foix and Joan of Artois. In 1315 the County of Foix passed to his elder brother Gaston II, while Roger Bernard received the Catalan viscounty of Castelbon, holding it as his brother's vassal.
By his wife Constance de Luna he fathered Roger Bernard IV and founded the Foix-Castelbon line, from which sprang the later counts Matthew and Isabella of Foix.