Leonardo da Vinci designed an armored tank as a circular, covered platform carrying several guns.
His 15th-century fighting vehicle was shaped like a broad conical shell, often compared with a turtle. Sloping armor was intended to deflect incoming weapons, while guns projected through openings around the platform. The vehicle was to move using wheels connected to internal gears turned by people inside.
Leonardo prepared the design for Ludovico Sforza, the Duke of Milan, while seeking military employment. The machine was never built in his lifetime, and historians debate whether a deliberate gearing problem in the drawing was meant to prevent others from using the design.
The vehicle is commonly called Leonardo’s tank, although it was not a modern tank. Twentieth-century tanks used engines, tracks, rotating turrets, and heavy armor. Leonardo’s concept was closer to a mobile armored gun platform, and its proposed human-powered mechanism would have made movement difficult.