His elder half-brother Gaston IV was the viscount of Béarn and the two maintained excellent fraternal relations, undertaking almost every military expedition jointly.
While Gaston was one of the heroes of the Crusade and consequently finds mention in many chronicles, Centule had not yet succeeded his brother at that point and was a mere nobleman, without a fief.
Centule, now armed with the forces of Bigorre behind him, joined Gaston in an alliance with Alfonso the Battler, King of Aragon and Navarre, on the successful expedition against Zaragoza in 1118.
For his part in the victory, Centule received a section of the city in fief of the king and twenty four villages in the Val d'Aran.
Centule married Estefania, daughter of Ramon Berenguer III, Count of Barcelona, and Dolça de Gévaudaun.