To the Japanese, the Beaufighter became known as "The Whispering Death"  which gives some idea of the speed at which one could suddenly appear, strike and turn for home. Beaufighters were also flown by the air forces of Britain, Australia, Canada, New Zealand and, in small numbers, the US. 

Britain's lack of long-range heavy fighters when the war started was a source of acute embarrassment to the RAF single-engined interceptors such as the Hurricane and Spitfire lacked the endurance for effective standing patrols, and it was soon discovered that the heavy long-range fighter would be invaluable to perform a wide variety of tasks. The result was a piece of true British improvisation--the Bristol Beaufighter, which entered service a year after the outbreak of war, at a time when it was most sorely needed.

Built as a company-funded long-range fighter (using major components from the earlier Beaufort torpedo-bomber), the prototype Beaufighter first flew on July 17,1939. This was little more than eight months after the design had been initiated. Exactly two weeks earlier, before the first flight, a production contract for 300 machines had been placed to specification F. 17/39. This seemingly desperate measure by the Air Ministry was, by 1938 to 1939, not uncommon, as it helped speed up the production of much-needed combat planes.

The fact that a heavy twin-engined fighter such as the Beaufighter was available as soon as the late autumn of 1940 was largely due to the foresight and enterprise of the Bristol Aeroplane Company in envisaging the probable need for a high-performance long-range fighter capable of undertaking duties of a more aggressive nature than those foreseen by official specifications. At the end of 1938 L. G. Frise and his design team began the design of what was virtually a fighter variant of the Beaufort general reconnaissance and torpedo-bomber. The initial proposal was framed, as far as possible, to meet the requirements of specification F.11/37, and envisaged an aeroplane using a large proportion of Beaufort components, including the wings, tail assembly and undercarriage, a pair of Hercules radial engines and carrying a battery of four 20-mm. Hispano cannon. The economy of the proposal was of obvious appeal to the government, struggling to meet the vast requirements of a major rearmament program, and, as the Type 156, four prototypes were ordered.