On 10 May 1940, the Wehrmacht launched its assault on the West. One element of the West’s response was the dispatch of RAF Bomber Command ‘heavy’ bombers at night over German industrial centers. These raids had only limited effectiveness, but the inability of the Luftwaffe to chase down RAF bombers at night so annoyed Wolfgang Falck that it swiftly resulted in the creation of a credible night fighter force. Initial trials had been flown with Bf 110s at dusk in Denmark in April, and 1. Nachtjagd.Division was founded in the summer of 1940. Its first few months were chaotic, with constant reorganizations of units, and reassignment of aircraft, but soon enough the night fighter arm was achieving steady victories—and losing crews at a similarly steady rate. Despite the efforts of senior leadership, the Nachtjagd constantly struggled to secure sufficient personnel or aircraft, and would spend most of its life playing catch up—its radar systems regularly outdone by RAF Bomber Command’s jamming capabilities, though the development of Schräge Musik and Wilde Sau did give the Nachtjagd an edge. The first specialist Luftwaffe night fighter—the Heinkel He 219—would be trialled only in 1943. Fully illustrated, this is a full chronological account of the night fighter units for the first part of World War II, covering major campaigns, the biographies of individual aces, and the details of the technology developed for the Nachtjagd.