45th Infantry Division was a 2nd line Territorial Army formation formed in 1939. Initially a duplicate of 43rd (Wessex) Infantry Division, they operated throughout the United Kingdom for the duration of the Second World War.
In December 1941, the Division was placed on the lower establishment. Major General H. de R. Morgan took command from 8th May 1941 to 11th January 1943, replaced by Major General J.K. Edwards on 12th January 1943. Edwards remained General Officer Commanding for the remainder of the Division’s wartime activity.
On 3rd February 1943, 45th Infantry Division moved to Northern Ireland. Elements of the Division scattered throughout Co. Down. While in Ulster, the Division undertook training under Headquarters British Troops Northern Ireland.
On 30th December 1943, 45th Infantry Division returned to England. Records suggest that double agents leaked the movements of the Division to and from Northern Ireland as part of Operation Fortitude in 1943. On 15th August 1944, 45th Infantry Division began to disperse under the reorganisation of Home Forces and ceased to exist on 30th August 1944.