Leonardo da Vinci designed an armored tank, also called his fighting vehicle, as a covered machine carrying cannons around its sloping shell.
The vehicle appears in a drawing from the late fifteenth century. Its conical, turtle-like cover was intended to protect the crew, while guns projected through openings around the perimeter. The machine was to be moved by crews turning internal cranks connected to wheels.
The design has an important limitation: the gearing shown in the drawing appears to contain a deliberate or accidental flaw that would prevent the wheels from turning correctly. Historians debate whether this was a mistake, a copying issue, or a way to keep the design from being freely used. In any case, no operational Leonardo tank is documented.
Calling it a tank is convenient but anachronistic. Modern tanks use engines, tracks, armor systems, and turrets developed much later. Leonardo’s vehicle was an early armored land-machine concept for warfare, not a working modern tank.