Cornwallis was also one of the senior officers in the September 1757 Raid on Rochefort which saw a failed amphibious descent on the French coastline. The vast force massed on the Isle of Wight before sailing for Rochefort. The fleet stopped at Île D'Aix and examined the French defences. General Sir John Mordaunt, head of the land forces, decided the defences were too strong to attack. He called a council of war. Cornwallis voted to retreat, while Admiral Edward Hawke, head of the naval forces, and James Wolfe, quartermaster general, voted to attack. Mordaunt and Cornwallis carried the day and the mission was abandoned.