Edward the Black Prince of Cornwall in 1337. He was guardian of the kingdom in his father's absence in 1338, 1340, and 1342. He was created Prince of Wales in 1343 and knighted by his father at La Hogne in 1346. In 1346 Prince Edward commanded the vanguard at the Battle of Crécy, his father intentionally leaving him to win the battle. He took part in Edward III's 1349 Calais expedition. In 1355 he was appointed the king's lieutenant in Gascony, and ordered to lead an army into Aquitaine on a chevauchée, during which he pillaged Avignonet and Castelnaudary, sacked Carcassonne, and plundered Narbonne.
Edward the Black Prince agreed, and after he had dined the prince chose twelve knights, four English, four Gascons, and four Bretons, to judge between himself and the marshal. After he had stated his case, d'Audrehem replied that he had not broken his word, for the army the prince led was not his own; he was merely in the pay of Peter. The knights considered that this view of the prince's position was sound, and gave their verdict for d'Audrehem. On 5 April 1367 the prince and Peter marched to Burgos, where they celebrated Easter. The prince, however, did not take up his quarters