Women gather at the recruitment office of Britain's Auxiliary Territorial Service (ATS), reformed in 1938 from the Women's Army Auxiliary Corps (WAACS) of World War I. By 1939 British women could also join the Women's Auxiliary Air Force (WAAF), the Women's Royal Naval Service (WRNS), and other military units. In December 1941, a British National Service Act began the conscription of childless widows and single women ages 20 to 30. British military women filled clerical, domestic and medical positions; drove and maintained vehicles; manned antiaircraft guns, barrage balloons, and radar stations; ferried aircraft; deciphered coded messages; and served as spies.
