Leonardo da Vinci’s proposed armored military vehicle with sloping sides is commonly described as a tank.
Leonardo designed the fighting vehicle in the late fifteenth century, probably for Ludovico Sforza. Its conical cover was reinforced with metal plates and shaped to deflect attacks. A group of wheels and internal gears was intended to move the platform, while soldiers inside could operate light cannons around its perimeter.
The design was never a modern tank in the technical sense. It had no engine, depended on human power, and the surviving drawing contains a mechanical problem that would make the vehicle move in the wrong direction if built exactly as shown. Some historians think the error may have been deliberate, since Leonardo sometimes concealed military designs in his notebooks.
The fighting vehicle is still important in the history of armored warfare because it combined protection, mobility, and mounted weapons in one concept. Modern tanks use engines, tracks, and turrets, features absent from Leonardo’s sketch.