During 1939-1941, Fighter Command lost around 1,000 aircrew. The reasons and circumstances for these losses are shown as crucial campaigns are enacted. Forty illustrations complement the loss details and appendices provide Fighter Command Orders of Battle at crucial periods in the conflict, plus details of the build-up of Night Fighter Squadrons during 1941, and a list of Wing Leaders. This particular work examines the sacrifice made by Fighter Command during the desperate early years of the war. Operational losses are recorded on a day-by-day basis, identifying the units concerned, the crews involved, and the aircraft type, service serial number and code letters where confirmed.