He joined the Order of Canon Regulars of Saint Augustine at Saint-Ruf. In 1358 he became prior of St.-Pierre-de-Dieu. In 1362 his older brother Guillaume was elected Pope Urban V and named him bishop of Avignon in December 1362. Four years later, in the consistory celebrated at Avignon on September 18, 1366, he was created Cardinal Priest of San Pietro in Vincoli. In September 1367 he was promoted to the rank of Cardinal-Bishop of Albano. He was Papal Vicar of Italy from 1368 until 1371. At the end of 1370 he was named archpriest of Lateran Basilica in succession to Cardinal Piere Roger de Beaufort, who was elected Pope Gregory XI. He became Dean of the Sacred College in November 1373. He did not participated in any of the papal conclaves celebrated during his cardinalate. He did not return to Rome with Gregory XI in 1376. After the outbreak of the Great Western Schism in 1378 he joined the obedience of Antipope Clement VII.