The Char D1 was a pre-World War II French tank.

The French plan of 1926, calling for the creation of a Light Infantry Support Tank, led to the development of the existing Renault NC1 prototype into the Char D1. One hundred and sixty vehicles of this type were produced between 1931 and 1935. There was a pre-series of ten vehicles and later 150 standard vehicles were built. Until 1936 the vehicles were fitted with Renault FT turrets because the intended cast ST2 turrets were not ready yet. The ST2 turret was armed with a short 47mm SA34 tank gun with a coaxial 7.5mm MG. The hull carried a 7.5mm MG in the bow. The type did not serve as an infantry support tank as originally intended, but as France's major battle tank of the early thirties; it was quickly phased out in 1937 because of its mechanical unreliability.

After World War I, France possessed a very large fleet of Renault FT light infantry support tanks. Although many of these were sold to other nations, over 2800 remained. In contrast to the United Kingdom, that after the war greatly reduced its armoured forces and scrapped any redundant AFVs, France maintained a large number of active or reserve armoured units (with an organic tank strength of about 1260) and all of the remaining Renault FTs were kept in working order. This implied that in the early twenties France had the strongest and most modern armoured force in the world, but this very fact led to a state of complacency. Development of new tank models was not seen as urgent, also because budgetary restraints would for the immediate future prohibit any further tank production anyway. When in 1922 General Jean Baptiste Eugène Estienne concluded an official study containing guidelines for long term tank design, no provisions were made for any new light infantry tank.

Char is the solid material that remains after light gases (e.g. coal gas) and tar have been driven out or released from a carbonaceous material during the initial stage of combustion, which is known as carbonization, charring, devolatilization or pyrolysis.

Further stages of efficient combustion (with or without char deposits) are known as gasification reactions, ending quickly when the reversible gas phase water gas shift reaction is reached.