Leonardo da Vinci’s armored vehicle resembled a tortoise when viewed from above.
His design, drawn around 1487, had a broad, conical shell made from wooden plates reinforced with metal. The sloping surface was intended to deflect projectiles, while openings around the lower edge allowed weapons to fire outward. The vehicle was designed to carry a crew and move using manually operated wheels.
The plan is commonly called Leonardo’s fighting vehicle or tank. It was not built in the fifteenth century, and the surviving drawing contains a mechanical problem: the gears as shown would not make the vehicle move correctly. Some historians think the error may have been deliberate or simply a drafting mistake.
Calling the machine a modern tank can be misleading. It had no engine, armor standards, or battlefield testing. Nevertheless, its turtle-like protective shell and all-around weapons make it one of Leonardo’s most recognizable military inventions.