 Being set on a military career he spent from 1758 until 1764 as an Ensign (junior officer) in the British Army.He succeeded to the earldom of Hopetoun on the death of his father in 1781.He was Lord-Lieutenant of Linlithgowshire from 1794 to 1816 and sat in the House of Lords as a Scottish Representative Peer from 1784 to 1790 and from 1794 to 1796.