112th Regiment RAC was formed on 1 November 1941 by the conversion to the armoured car role of the 9th Battalion, Sherwood Foresters (Nottinghamshire and Derbyshire Regiment). This was an infantry battalion raised in 1939 that had seen action at the Battle of Dunkirk, originally as part of 139th Brigade of 46th Division, and had since been serving in the lorried infantry role in the Support Group of 1st Armoured Division. The battalion had been under orders to accompany 1st Armoured to the Middle East, but these were cancelled and the men returned their tropical uniforms to store.