Leonardo da Vinci designed an armoured tank as a military vehicle with a covered, conical body and internal wheels.
The vehicle appears in a drawing usually dated to around 1487–1489, probably prepared for Ludovico Sforza, Duke of Milan. Its sloping armour was intended to deflect incoming projectiles, while several light cannons projected through openings around the platform.
The design was powered by four men turning cranks connected to gears. Historians have noted that the surviving drawing contains a gearing problem that would make the vehicle move backward if built exactly as shown. Some researchers think the error was deliberate, concealing the design from potential enemies.
Leonardo’s vehicle was not a modern tank: it had no engine, enclosed crew compartment, or rotating turret. Nevertheless, its armoured shape, mobile weapons, and crew-operated propulsion make it a famous early concept for an armoured fighting vehicle.