Leonardo da Vinci’s armored military vehicle design is commonly called a tank.
Leonardo drew the fighting vehicle around 1487–1489 while working for Ludovico Sforza in Milan. The design resembles a truncated cone covered by angled metal plates, with a circular platform carrying light cannons. The sloping armor was intended to deflect incoming projectiles, while teams of men inside would turn cranks connected to wheels.
The vehicle is often described as a prototype tank, but it was only a paper design and was never built for Renaissance warfare. A frequently repeated story says Leonardo deliberately included a flaw in the gears to keep the design from being used against Florence or Milan; historians debate whether this was intentional or simply a drawing error. Modern tanks developed from industrial-era armored vehicles and tracked propulsion, not directly from Leonardo’s machine.