The design of the Fulmar was based on that of the earlier Fairey P.4/34, a land-based fighter developed during 1936 as a replacement for the Fairey Battle light bomber. Fairey had redesigned the aircraft as a navalised observation/fighter aircraft to satisfy the requirements of Specification O.8/38, for which it was selected. Although its performance (like that of its Battle antecedent) was unspectacular, the Fulmar was a reliable, sturdy aircraft with long range and an effective armament of eight machine guns; the type could also be put into production relatively quickly. On 4 January 1940, the first production aircraft made its first flight and delivery commenced shortly thereafter, while production of an improved model, the Fulmar Mk II, started during January 1941. Fairey produced a total of 600 Fulmars at its Stockport factory between January 1940 and December 1942.