The Auxiliary Territorial Service was the women's branch of the British Army during the Second World War. It was formed on 9 September 1938, initially as a women's voluntary service, and existed until 1 February 1949, when it was merged into the Women's Royal Army Corps.

The London Electrical Engineers was a Volunteer unit of the British Army's Royal Engineers founded in 1897. It pioneered the use of searchlights (S/Ls) for port defence before World War I and for anti-aircraft (AA) defence during the war. In the interwar period it formed the two senior searchlight regiments of the Territorial Army, which defended Southern England during The Blitz. Detachments later served in the Battle of Crete and Siege of Tobruk.