France worked diligently to recover from the destruction and losses suffered during WWII, and their efforts included rebuilding and modernizing their armed forces.

Jet propulsion was the future of fighters, but France was behind the other allied powers in developing it. French engineers had only begun familiarizing themselves with jet technology because the German occupation prevented them from studying it.

Regardless, the French Air Force needed natively-produced jet aircraft. In 1951, the French Air Force issued specific requirements for a multi-purpose jet aircraft capable of bombing, intercepting, and attacking ground targets. Encouraged by the test results of their SO.4000 design, SNCASO continued developing the project to meet the new requirements--and ultimately created the SO.4050 Vautour.

The initial order for the new design called for three prototypes to be built, the first of which conducted its maiden flight on October 16th, 1952 and demonstrated promising results. Additional testing proved favorable, and resulted in an order for five pre-production aircraft to test different propulsion options. 

Two engines tested were the Rolls-Royce Avon and Armstrong-Siddeley Sapphire engines, but it was ultimately decided to use the French-designed Snecma Atar engine because it was deemed sufficiently powerful to power the Vautour. 

This design entered mass production in the early 1950s under the designation SO.4050 Vautour II in three variants. Each variant entered service with the French Air Force in 1958, and would continue to be actively used until 1979. 

The Vautour never saw any combat under French use, although several Vautours were exported to Israel and saw extensive combat use in multiple regional conflicts, including the Six Day War and the War of Attrition. 

Nearly 150 Vautours were built, although in the 1980s all of them would be quickly replaced by the famous Dassault Mirage.