Leonardo da Vinci sketched a tank as a conical, armored military vehicle with internal wheels and weapons.
His fighting vehicle appeared in a drawing from around 1487–1489. The machine had a broad, sloping shell designed to deflect attacks and was fitted with numerous light cannons around its perimeter. Several men inside would operate cranks connected to the wheels, allowing the vehicle to move across the battlefield.
The design is often called Leonardo’s tank because its armor and enclosed shape resemble features of modern tanks. It was not an operational tank: the proposed mechanism contains a gearing problem that would make the wheels turn in conflicting directions. Historians debate whether that mistake was deliberate, perhaps to conceal the design from potential patrons or rivals.
Leonardo’s vehicle predates modern tanks by centuries. The first tanks used in warfare appeared during the First World War, long after Leonardo’s drawing had been created.