Leonardo da Vinci’s armored military vehicle is commonly called a tank.
Leonardo sketched the vehicle around 1487–1489. Its conical wooden shell was covered with armor plates and was intended to protect soldiers inside. A ring of light cannons around the lower edge would allow the crew to fire in several directions.
The vehicle was to be powered by cranks operated by men inside. Its design included wheels and gears, but the surviving drawing contains a mechanical problem that would prevent the vehicle from moving as shown. Some historians think this may have been deliberate, because Leonardo’s patron, Ludovico Sforza, was a military ruler and Leonardo may not have wanted to reveal every detail.
The design is not an actual modern tank and was never built as a working battlefield vehicle in Leonardo’s lifetime. The familiar name “tank” comes from much later armored vehicles, especially those developed during World War I.