Leonardo da Vinci’s armored tank design featured a circular vehicle moved by four men turning cranks.
Leonardo designed the fighting vehicle in the late fifteenth century, probably around 1485. Its conical, turtle-like shell was covered with metal plates and fitted with light cannons around the perimeter. The vehicle was intended to advance across a battlefield while protecting its crew and allowing fire in several directions.
The surviving drawing contains a famous mechanical problem: the gearing, as usually reconstructed, would make the wheels turn in opposite directions. Some historians have suggested that this may have been deliberate, hiding the design from unauthorized readers or reflecting an error in the drawing. The vehicle was never built for battle.
The design is commonly called Leonardo’s tank, but it was not a modern tracked tank. It had wheels, no engine, and depended on human power. Its importance lies in combining armor, mobility, and all-around firepower in one early military concept.