 Arran was a Lord of the Bedchamber to King William III, a Lieutenant-General in the Army, Colonel of the 3rd Troop of Horse Guards, Governor of Dover Castle, and Master-General of the Ordnance from 1712 to 1714.On 3 June 1705 he married Elizabeth Crew, Countess of Arran, daughter of Thomas Crew, 2nd Baron Crew and his second wife, the former Anne Airmine, daughter of Sir William Airmine, 2nd Baronet in Oatlands, at Weybridge in Surrey.The marriage was childless.