Leonardo da Vinci’s armored circular war machine was his fighting vehicle.
Leonardo designed the fighting vehicle around 1487–1489 while working in Milan. The machine had a conical, covered body resembling a tortoise shell and was intended to carry cannons around its perimeter. Inside, men would turn cranks connected to wheels so the vehicle could move across a battlefield while shielding its crew.
The design is often popularly called Leonardo’s tank, although that modern label can be misleading. The vehicle was never built or used in Renaissance warfare, and the surviving drawing contains a mechanical problem: the gear arrangement appears to make the wheels turn in opposite directions. Some historians have suggested this may have been deliberate sabotage or a design error.
Unlike a modern tank, Leonardo’s vehicle had no engine, turret, tracked suspension, or practical tested armor system. It remains significant as an early conceptual armored fighting vehicle.