Eventually returning home, the sixteen-year-old nobleman seduced and married the fiancee of his absent elder brother, Viscount Aboyne. He served on both sides in the Scottish Civil War, playing an important role in his father's occupation of Aberdeen in 1646, where he engaged an enemy cavalry commander in single combat and then storming the town. Going into exile after the defeat of the royalists, he traveled again to France; in rapid succession, he succeeded his brother and father as Earl of Enzie and Marquess of Gordon, and by 1651, he was allowed to return to Scotland, even though he refused to conform to the Presbyterian Church of Scotland (he was probably a Roman Catholic).