Leonardo da Vinci designed a tank-like armored fighting vehicle in a famous 1487 sketch.
The machine has a conical cover inspired by a tortoise shell. Its armor was intended to protect soldiers inside, while several light cannons projected through openings around the sides. The vehicle would have been moved by people turning cranks connected to gears and wheels.
Leonardo’s design was not a modern tank in the technical sense, and there is no evidence that a full working vehicle was built in his lifetime. A commonly repeated story says the gears were deliberately drawn incorrectly, but historians do not agree that this was Leonardo’s intention. The drawing may instead contain a mechanical error or represent an unfinished design.
The modern word “tank” belongs to twentieth-century armored warfare. Leonardo’s machine is better understood as an early concept for an armored vehicle, centuries before tracked tanks appeared in World War I.