But when Bernard of Septimania was captured by Charles the Bald for rebellion against his lord and executed in 844, the king bestowed his county of Toulouse on Fredelo.
Pepin II of Aquitaine, who was leading the revolt against Charles, appointed Bernard's heir William to the county of Toulouse.
Fredelo, then in control of Toulouse, taking advantage of William's absence, opened the gates of the city to his sovereign and was reconfirmed in his possession of it.
Fredelo received the County of Carcassonne in 850 and died in 852, leaving his titles to his brother Raymond.
By his wife Oda, he left one daughter named Udalgarda who married Bernard Plantapilosa.