Leonardo da Vinci designed an armored tank with a conical cover and internal drive wheels.
The vehicle appears in Leonardo’s late-15th-century engineering studies, probably made for Ludovico Sforza, the ruler of Milan. Its sloping shell was intended to deflect incoming projectiles, while a ring of cannons pointed outward around the lower edge.
The design was powered by four operators turning cranks connected to gears. Because the gearing arrangement would make the wheels turn in opposite directions, some historians think Leonardo deliberately introduced that error to prevent an enemy from using the design. Others regard it as an ordinary design mistake.
It was never built as a working Renaissance battlefield vehicle. Modern descriptions often call it Leonardo’s tank, but it was a proposed armored fighting vehicle rather than a modern tank with an engine, turret, or tracks.