In 1332 he was one of the disinherited barons who invaded Scotland. He fought in the Battle of Dupplin Muir on 11 August 1332, where he assisted in the victory of Edward Balliol.
He fought in the Battle of Neville's Cross on 17 October 1346, where he was one of the commanders.
On his death, none of the legitimate heirs of his grandfather, 8th Earl of Angus, where summoned under his titles.