The regiment had its origins in independent Anti-Aircraft Searchlight Companies of the Royal Engineers formed in the Territorial Army (TA) during 1924.

The Army Council considered that 'the provision of accommodation must precede the call for men in order to ensure success', pointing out that 'The new Anti-Aircraft units are of great importance and recruiting, which is slow at present, is likely to be impossible without adequate headquarters to attract the personnel'.

[6] In the event, 315 AASL Company was accommodated at Mitcham Road Barracks in Croydon, originally built in 1794 as a depot for recruits to the Foot Guards, but used by local Territorial units since at least 1859.

The battalion was subordinated to 27th (Home Counties) Anti-Aircraft Group (later termed a Brigade) based at RAF Kenley in Surrey, forming part of 1st AA Division.

[16][18][19] Some of these airfields were attacked during June, some searchlight equipment was damaged by bomb splinters, and one site engaged an enemy aircraft with its Lewis gun.

[24] As German night air raids on the UK intensified (The Blitz), 30 S/L Rgt sent detachments to London in September and then to Sheffield in November to assist in their defence.

[25] In March 1941, German bombers began dropping mines in the Humber Estuary, and 39 AA Bde ordered 30 Searchlight Regt to establish a mobile detachment to help the defenders engage these raiders.

[2][26] During the summer of 1941 the regiment's batteries were successively relieved from fire duties at Bristol and went to Birmingham for rest and retraining for a mobile role.

[2][27] The Croydon and Kingston Batteries, 315 and 316, had been sent by sea with 18th Infantry Division bound for the Middle East, but were diverted to Malaya, where they were attached to 5th Searchlight Regiment.

As Light Anti-Aircraft/Searchlight units equipped with Bofors guns they were involved in the defence of airfields against Japanese attack before retreating to be captured in the Fall of Singapore.

[22][42] 567 and 568 Batteries continued as independent units in 1944, serving with British Land Forces Adriatic; they were disbanded on 15 February 1946 and 7 November 1945 respectively.

[22][46][49][51][52] To hear an Imperial War Museum interview with Sergeant Percy Mutimer on his experiences with 316 Searchlight Battery in peacetime Kingston, in the Malayan campaign, and as a Japanese POW, visit http://www.iwm.org.uk/collections/item/object/80004760.