Edward was made Duke of Cornwall, the first English dukedom, 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 Hougue 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