The engineers of the Marcel-Bloch aviation design company envisioned a fighter equipped with the new powerful air-cooled Gnôme-Rhône 14R engine as early as 1939. Initially, the engine was intended for installation on the airframe of the MB.152 fighter, but the weight and dimensions of the engine required the fuselage to be significantly redesigned. With the beginning of MB.155 fighter mass production design works were concentrated on adapting its airframe for this highly promising engine. However, the capitulation of France and German occupation prevented the work on the MB.157 from being finished. In spite of the fact that the Dewoitine D.520 was selected as the main fighter of occupied France’s Air Force, French command expressed interest in creating a competitor to the Dewoitine. The interrupted work on the MB.157 was resumed, and soon a prototype of a new fighter with the GR.14 engine was built. In flight tests, attended by executive officers of the Luftwaffe, the MB.157 amazed observers by reaching speeds of over 700 km/h at a high altitude. German military experts decided to carefully study the finished prototypes and forced France to give the MB.157 to the Luftwaffe. It soon emerged that in spite of its impressive speed, the fighter wasn’t ready for mass production due to partial breakdowns in the turbocharger and engine, along with a low rate of climb to the heights where the MB.157 could fully unleash its potential speed.