The Potez 630 and its derivatives were a family of twin-engined, multirole aircraft developed for the French Air Force in the late 1930s. The design was a contemporary of the British Bristol Blenheim (which was larger and designed purely as a bomber) and the German Messerschmitt Bf 110 (which was designed purely as a fighter). The Potez 630 was in use by several operators during the Second World War. Following the Battle of France, both the Vichy French Air Force and Free French Air Forces used the type; a number of captured aircraft were operated by several air wings of the Axis powers. After the end of the conflict in 1945, a handful of aircraft were used for training purposes for some time. Development Origins On 31 October 1934, the French Ministry of Air issued a specification for a heavy fighter. The specification demanded the aircraft be capable of performing three principal roles: fighter direction, in which it was required to lead formations of single-engine fighters with sufficient maneuverability; day attack, in which the type was also to escort friendly close air support and bomber aircraft; and nightfighter operations. Specified performance details included a maximum speed of 450 km/h at 4,000 meters, a 300 km/h cruising speed, and an endurance of at least four hours. Armament requirements included two fixed forward-firing 20 mm cannons and a single machine gun to the rear for self-defence. The sought aircraft was also required to accommodate two/three seats along with a twin-engine configuration; however, some of the performance limitations imposed upon the aircraft, such as the maximum weight, served to restrict the range of suitable engines to power the type. The original Potez 630 was developed to meet this specification; two variants of the aircraft were originally submitted for consideration, one (the 630) powered by Hispano-Suiza 14AB radial engines and the other (the 631) with the Gnome-Rhône 14N. Other companies also produced submissions in response, including Breguet Aviation, Hanriot, Chantiers aéronavals Étienne Romano, and Loire-Nieuport. Each of the competing manufacturers were requested to produce a single prototype for evaluation at their own expense; work on the first prototype, designated as the Potez 630-01, commenced in April 1935. In addition to the Potez 630, the same specification had ultimately resulted in the successful Breguet 690 series of attack aircraft. On 25 April 1936, the Potez 630-01, equipped with a pair of 580 hp Hispano-Suiza 14,