In 1542, he joined the Dauphin in Picardy and Luxembourg. In 1543, he was part of the French command against the English and Spanish in Picardy. In the Italian War of 1542–1546, he was charged with the conquest of Savoy. He advised against the Battle of Ceresole (1544), but was overruled by Blaise de Lasseran-Massencôme, seigneur de Montluc, who won the battle.