Leonardo da Vinci sketched an armored tank as a covered, conical military vehicle powered by eight men.
His design, drawn around 1487–1489, used a circular platform surrounded by sloped armor plates. The sloping surfaces were intended to deflect enemy fire, while several light cannons projected through openings around the vehicle. Cranks connected to gears would turn the wheels.
The tank was never built in Leonardo’s lifetime, and the surviving drawing is a design concept rather than evidence of a working prototype. A famous apparent flaw is that some gear arrangements would make the vehicle move backward; historians debate whether this was deliberate sabotage or simply an error in the sketch. Leonardo’s machine was also not a modern tank: it had no engine, enclosed crew compartment, or continuous tracks.