How many victories did No. 604 Squadron, the RAF night-fighter squadron, claim?

In late September 1940 the squadron received its first Bristol Beaufighter, armed with four 20 mm Hispano-Suiza HS.404 cannons under the nose and fitted with improved Mark IV AI radar equipment. The conversion to the Beaufighter took place between September 1940 and January 1941. As one of the few squadrons so equipped, No. 604 was responsible for the night defense of the United Kingdom during the Blitz, from late 1940 until mid-May 1941, when most of the Luftwaffe's bomber units left to take part in the invasion of Russia.

By then the squadron had claimed 50 aerial victories, fourteen of them by Flight Lieutenant John Cunningham. In total, it claimed about 127 aerial victories during the war, 41 of them from May 1944 onward.

No. 604 (County of Middlesex) Squadron spent most of the Second World War as a night-fighter squadron, flying both defensive and offensive missions. Among its crews was the pairing of John Cunningham and C. F. Rawnsley, one of the best British night-fighter crews of the war. Between them they received nine British decorations, and Rawnsley later wrote a book about their experiences.