Leonardo da Vinci's conical armored military vehicle with multiple cannons was an armoured tank.
Leonardo designed the fighting vehicle around 1487 while working for Ludovico Sforza in Milan. The machine was a covered, conical vehicle intended to protect soldiers while carrying weapons. Its sloped armor could deflect projectiles, and a ring of light cannons was meant to fire in several directions.
The vehicle was designed to be moved by people turning cranks connected to wheels. Modern reconstructions have pointed out that the surviving drawing appears to contain a mechanical error: some gears would make the wheels turn in opposing directions. Historians disagree about whether this was an error, a deliberate safeguard, or a problem introduced during copying.
Leonardo's vehicle was not a modern tank in the engineering sense, because it was never produced as an operational armored fighting vehicle. The familiar label reflects its enclosed, armored, wheeled form and its role as a proposed battlefield machine.