This is the little-known story of the Women’s Auxiliary Air Force, the women’s branch of the Royal Air Force in the Second World War, and the vital work they did behind the scenes to ensure the success of some of the most important missions of the war. During the Battle of Britain, for example, WAAF personnel worked in the radar network and the Dowding System, the world’s most sophisticated air defence system, as well as in the Y Listening Service, intercepting German ground-to-air and air-to-air communications. During the Blitz, they worked with ground-controlled interception radar to aid Fighter and Bomber Command in protecting Britain’s civilian population from German area bombing. They assisted with the Allied offensive bombing campaign in various capacities, including working behind the scenes leading up to the ‘Thousand Bomber Raids’. It was WAAF personnel who were behind the discovery of the terrifying German V Weapons and jet-propelled aircraft and assisted with the sinking of German battleships such as the Tirpitz. The WAAF collected and disseminated intelligence ahead of the Normandy landings in June 1944 and worked in signals intelligence throughout the landings and the Allied advance into Europe. They were also present in their hundreds at Bletchley Park, working with the Government Code and Cypher School on air intelligence and liaising with the RAF’s Y Service. Though the work and memory of the pilots of Fighter and Bomber Commands are rightfully revered and treasured, their success was made possible by the WAAF working behind the scenes. This book aims to recover this missing piece of history, granting the WAAF the recognition they deserve for their wartime contribution to British military intelligence.