In 1934, the Service Technique Aéronautique (Aeronautical Technical Service) of the Armée de l'Air issued the "C1 design" requirement for a new and completely modern single-seat fighter with a monoplane layout and retracting landing gear.
Morane-Saulnier's response was the M.S.405 developed by Engineer in Chief Paul-René Gauthier. The MS.405 was a low-wing monoplane of mixed construction, with fabric-covered wooden tail, but a bonded metal/wood material (Plymax) skin fixed to duralumin tubing. Plymax consisted of a thin sheet of duralumin bonded to a thicker sheet of plywood. Morane-Saulnier had a long history of producing warplanes dating back to pre-World War I years, but in the inter-war period, they had concentrated on civil designs. The aircraft was a departure for them, being their first low-wing monoplane, first with an enclosed cockpit, and first design with retracting landing gear. Prior to this, their most modern designs were fixed-gear parasol monoplanes.
The new 641.3 kW (860 hp) Hispano-Suiza 12Ygrs engine driving a two-pitch Chauvière propeller powered the first M.S405-1 prototype, which flew on 8 August 1935. Development was very slow, and the second M.S.405-2 prototype with a 671.1 kW (900 hp) Hispano-Suiza 12Ycrs engine didn't fly until 20 January 1937, almost a year and a half later. With the new engine the fighter reached 443 km/h (275 mph), fast enough to secure an order for a further 16 pre-production prototypes, each including improvements on the previous version.
The result of these changes was the M.S.406. The two main changes were the inclusion of a new wing structure which saved weight, and a retractable radiator under the fuselage. Powered by the production 641.3 kW (860 hp) HS 12Y-31 engine, the new design was over 8 km/h (5 mph) faster than the 405, at 489 km/h (304 mph). Armament consisted of a 20 mm (0.787 in) Hispano-Suiza HS.9 or 404 cannon with 60 rounds in the V of the engine and fired through the propeller hub, and two 7.5 mm (0.295 in) MAC 1934 machine guns (one in each wing, each with 300 rounds). A weakness of the MAC 1934 was its operation at high altitudes. It was found that at altitudes over 20,000 ft, the guns had a tendency to freeze. Heaters were added to the guns for high-altitude use.
While the 406s were entering service in 1939, an upgrade series was started to improve the design. The result was the M.S.410, which included a stronger wing, simpler fixed radiator in place of the earlier retractable design, four belt-fed MAC guns in place of the earlier two drum-fed weapons, and exhaust ejectors for additional thrust. The added thrust boosted the top speed to 509 km/h (316 mph), an improvement of about 16 km/h (10 mph) over the 406.
Production had just started when France fell, and only five examples had been completed. Production was allowed to continue under German supervision, converting earlier 406s to the 410 standard, but many of these received only the new wings. Altogether 74 planes were modified.
A single example of the M.S.411 was constructed by converting the 12th aircraft of the pre-production line with the 406 wing and the 745.7 kW (1,000 hp) Hispano-Suiza 12Y-45 engine. A later modification was started as the M.S.412 with the 783.0 kW (1,050 hp) Hispano-Suiza 12Y-51 engine, but this was not completed by the time the war ended.
In 1939, Hispano started prototype deliveries of the new Hispano-Suiza 12Z engine of 969.4 kW (1,300 hp). One was fitted to a modified 410 to create the M.S.450, giving dramatic improvements in performance, especially at altitude. However the engine did not enter production before France fell, and the similarly modified Dewoitine D.520 (the D.523/D.551) was considered a better design for the engine anyway.
The M.S.406 airframe was also used in a number of other projects. The M.S.430 was a two-seat trainer built by inserting a "plug" in the central fuselage with an extra cockpit for the trainee pilot, and using the much less powerful 290.8 kW (390 hp) Salmson 9 radial engine. The M.S.435 was a more powerful version with the 410.1 kW (550 hp) Gnome-Rhône 9K engine.