What type of armored vehicle did Leonardo da Vinci design for battlefield use?

Leonardo da Vinci designed an armored tank-like fighting vehicle for battlefield use.

His c. 1487 design shows a conical, turtle-shaped cover mounted on wheels and covered with metal plates. The vehicle was intended to protect soldiers inside while they operated a ring of light cannons aimed through openings around the structure. Its sloped exterior would also have helped deflect incoming projectiles.

The machine was never built or used in Leonardo’s lifetime. The surviving drawing includes a mechanical problem: the gears as shown would make the wheels turn in opposite directions. Some historians think this may have been an intentional error to keep the military design from being used by others, although that interpretation is not proven.

Calling it a “tank” is a modern comparison. Leonardo’s vehicle lacked an engine, a rotating turret, and the tracked propulsion system associated with modern tanks. It is better understood as an armored wheeled assault vehicle or mobile gun platform.