Lord Glasgow was a captain in the 33rd Regiment of Foot, and took part in the Battle of Fontenoy on 30 April 1745 and the Battle of Lauffeld on 2 July 1747, being wounded on both occasions. Between 1755 and 1757, he was Lord Rector of the University of Glasgow and between 1764 and 1772, he was Lord High Commissioner to the General Assembly of the Church of Scotland.