In 1731 Alexander Colville, 7th Lord Colville of Culross joined the Navy. He soon obtained his own command and by in 1744 became captain of HMS Leopard (1741), a fifty gun frigate. He was later promoted to commodore and obtained command of HMS Northumberland (1750) and sailed to America in 1755 during the Seven Years' War. In 1759 Colville forced the French to raise the siege of Quebec and retreat. In 1769 Colville was promoted to the rank of Vice Admiral.