The Renault FT-17 was a French light tank from the First World War. The first prototypes of the vehicle were created at the end of 1916, and serial production started in 1917 and lasted until 1919, ending with the production of about 3,700-4,000 cars. The tank was powered by a single 35hp Renault 18CV carburetor engine. Its main armament was either a single Puteaux cannon 37mm L / 21 or 1 7.92 mm Hotchkiss machine gun. The armament was mounted in a round cast tower by Renault or a conical riveted tower by Berliet. Renault FT-17 was one of the most revolutionary tank designs of World War I, as it was the first vehicle in history to feature a classic tank design: the driver's seat was located in the front, the combat compartment with a rotating turret was placed in the middle, and the engine compartment at the rear. This layout has been preserved in tanks to this day, due to its high functionality. The Renault FT-17 was also small in size and had a crew of only two people, which was unheard of compared to other tanks of that period! Renault FT-17 also received a special "tail" at the rear of the fuselage, which made it easier for it to overcome the trenches on the battlefield. The vehicle, which debuted on the battlefield on May 31, 1918, fought until the end of the war, proving to be the most effective and reliable tank of the French army. After 1918, it was widely exported (e.g. to Poland or the USA), often constituting the first tank in the history of the armed forces of a given country. The Italian FIAT 3000 tank and the Soviet MS-1 were also based on its design. Renault FT-17 remained in the arsenals of the French and Polish armies until the outbreak of World War II, but at that time it was perceived as completely obsolete design.The first tanks and units composed of them appeared in the French army during World War I, as a remedy for the stalemate of the positional war of the Western front. Interestingly, however, unlike Great Britain, the initiative to build them came from French economic entities and defense companies, rather than the French army. On the other hand, among the French officers, there were many supporters of introducing new weapons to the line, and Colonel Estienne deserves special emphasis. It is assumed that the first tanks of the French armed forces were the not very successful Schneider CA1 vehicles, and from April 1917, another heavy tank - Saint-Chamond - was delivered to the units. In the same 1917, a truly revolutionary vehicle was introduced into service - the Renault FT-17 light tank, widely recognized as the most successful tank in its class in the Great War. This vehicle had a rotating turret with main armament, was much cheaper to produce than the Schneider CA1 or Saint-Chamond, and was better suited to combat in the trench war realities. These tanks played a great role in the French and Allied offensives at the end of the First World War, contributing in no small way to the defeat of the German army.