Like other courtiers, he also proved his loyalty by taking up arms on the king's behalf. In 1544, aged at least 53, he enlisted in an army of 40,000 under the dukes of Norfolk and Suffolk to invade in northern France, as part of the Italian War of 1542–1546. However, the campaign became bogged down in protracted sieges and ended inconclusively after a few months, when Charles V, Henry VIII's main ally in the war, made a separate peace.