Leonardo da Vinci’s armored tank was a conical-covered fighting vehicle with cannons projecting around its sides.
Leonardo sketched the machine in the 1480s while seeking military commissions from Ludovico Sforza, Duke of Milan. Its shell resembled a tortoise, with sloping armor intended to deflect missiles. A ring of light cannons would have allowed the crew to fire in several directions while remaining protected.
The vehicle was supposed to move through internal cranks connected to wheels, but the arrangement in the surviving drawing would not work as shown: some gears appear to be oriented incorrectly. Historians debate whether this was deliberate, perhaps to keep the design secret, or simply an error. It was not a modern tank, because it lacked an engine and was never built or used in battle.