In the Seven Years' War, he served as adjutant in the staff of Duke Ferdinand of Brunswick and on 1 August 1759 was wounded at Minden. On 14 October 1760 he commanded a Light Company at the Battle of Campen, where he was again wounded. One year later, as Lt. Colonel of the 98th Regiment of Foot (1761), he participated in the Capture of Belle Île, off the coast of Brittany. Next, he served at the Battle of Havana in 1762. Later, he was on the staff of Wilhelm, Count of Schaumburg-Lippe during the Spanish invasion of Portugal (1762). In 1763 he retired on half-pay, but in 1772 he received a promotion to Colonel and served as aide-de-camp to King George III.