He was commissioned, after his father had given William III some encouragement, as colonel of Lord Lorne's Regiment of Foot, a regiment entirely raised by the Argyll family, on 7 April 1694. Campbell served briefly on the continent in the Nine Years' War before the regiment was disbanded in 1698. He also served under the Duke of Marlborough at the Battle of Kaiserwerth in April 1702 during the War of the Spanish Succession. He was appointed a Knight of the Order of the Thistle later that year.