 474th (Ind) S/L Bty was formally mobilised for active service in June 1943 and in August was joined by its own Royal Electrical and Mechanical Engineers (REME) workshop, which had formed at Bestwood Camp, Nottingham in May as 'M' S/L Battery Workshop.After attending various training camps and field exercises, the battery moved to Silverstone in Northamptonshire and joined 100 AA Bde, one of the formations preparing for Operation Overlord, the planned Allied invasion of Normandy.In February 1944, Battery HQ moved to Caterham in Surrey, where it came under the command of 80 AA Bde, one of the Overlord assault formations, though Troops of 8 lights were detached until April, providing 'Canopy' cover for RAF Colerne and RAF Manston.