What type of vehicle did Leonardo da Vinci sketch with a conical armored cover and eight crew members?

Leonardo da Vinci sketched an armored fighting vehicle with a conical armored cover and eight crew members.

The design appears in Leonardo’s notebooks from around 1487. Its sloped cover was intended to deflect incoming missiles, while openings around the lower structure allowed weapons to fire outward. Inside, men would turn cranks connected to wheels.

The vehicle is often called Leonardo’s tank because its appearance resembles a modern tank. However, it was not a working tank, and the drawing does not show a complete practical engineering solution. The proposed mechanism would have been extremely difficult for its crew to operate.

A frequently repeated story says Leonardo deliberately included a gearing error to prevent the design from being built. Historians debate that interpretation; the design may simply reflect an unfinished or inconsistent notebook sketch. Its historical importance is that it combines armor, mobility, and distributed firepower centuries before modern armored vehicles.