At the end of 1934 - before the existence of the Luftwaffe had been officially declared, Germany had less than six hundred front-line combat aircraft. But by the outbreak of the Second World War, the number had risen to more than three and a half thousand. Thirty percent of these were single-engined fighters and for the next six years, one small but rugged aeroplane would form the very backbone of the German fighter force - Messerschmitt BF109. This legendary machine remained in continuous action from 1939 to 1945 and in doing so, it shot down twice as many aircraft as any other fighter in history.