Following the outbreak of the Second World War, he joined the British Expeditionary Force, and was appointed as a Chief Liaison Officer on 4 September 1939. In January 1940, he was appointed to the colonelcies of the Ulster Anti-Aircraft Regiments, the Royal Artillery and the Territorial Army. He was slightly wounded in 1940 when his staff car was attacked from the air. In August 1940, he was appointed Chief Liaison Officer, GHQ Home Forces. He also became second-in-command of the 20th Armoured Brigade that year, and was promoted to lieutenant-general on 17 September 1941. On 27 October 1944, he was promoted to the rank of full general.