In the 1930s the increasing need for anti-aircraft (AA) defence for Britain's cities was addressed by converting a number of TA units into searchlight (S/L) battalions of the Royal Engineers (RE).

[2][11][9][12][13][14][15][16][17] The regiment supplied a cadre of experienced officers and men to 231st S/L Training Rgt at Blandford Camp where it provided the basis for a new 522 S/L Bty formed on 14 November 1940.

[22][23][24] By early 1944, AA Command was being forced to release manpower for overseas service, particularly Operation Overlord (the planned Allied invasion of Normandy) and most S/L regiments lost one of their four batteries; on 6 March 1944 394 S/L Bty began disbanding, completing the process by 3 April.

This HQ had been brought down from Scotland and given responsibility for the 'Overlord' ports and assembly camps in the Solent–Portsmouth area, which had been bombed a number of times during the 'Baby Blitz' of early 1944.

[8][24][25][26][27][28] Shortly after D Day the first V-1 flying bombs (codenamed 'Divers') were launched against London, and the defences of 2 and 6 AA Groups were reorganised in Operation Diver to combat these.

[26][29][30] By the end of 1944 the German Luftwaffe was suffering from such shortages of pilots, aircraft and fuel that serious aerial attacks on the United Kingdom could be discounted.

At the same time 21st Army Group fighting in North West Europe was suffering a severe manpower shortage, particularly among the infantry.

[2][3][8][9][10][34][35][36][37] In February the surplus (older or unfit) men were sent to Bursledon, near Southampton, where 82nd S/L Rgt was acting as a holding unit.