Christison was General Officer Commanding-in-Chief (GOC-in-C) of Northern Command from 1946 to 1947; he was then GOC-in-C of Scottish Command and Governor of Edinburgh Castle from 1947 to 1949 He was promoted to full general in August 1947. He held the honorary appointments of aide-de-camp general to the King (1947 to 1949) and Colonel of his regiment, the Duke of Wellington's Regiment (1947 to 1957). In 1947 Christison was appointed Colonel of the 10th Gurkha Rifles and in late 1949 he was also made Colonel of a Territorial artillery unit.