Leonardo da Vinci's 1487 military design was an armored tank protected by sloped armor and armed with guns.
The machine appears in a famous sketch showing a conical, turtle-like cover mounted on wheels. The sloped exterior was intended to deflect projectiles, while multiple light cannons would fire through openings around the vehicle. Men inside would turn cranks connected to the wheels.
The design is often called Leonardo's fighting vehicle or Leonardo's tank. It was not a working tank, and the original drawing contains a mechanical inconsistency: the proposed gearing would make the wheels turn in opposite directions. Historians have debated whether that error was accidental or deliberate.
Unlike modern tanks, Leonardo's vehicle had no engine, turret, tracks, or demonstrated battlefield role. Its importance lies in combining protection, mobility, and concentrated firepower in a single early armored-vehicle concept.