What vehicle did Leonardo da Vinci design with sloped armor and internal cranks for soldiers to operate?

Leonardo da Vinci designed an armored fighting vehicle with sloped armor and internal cranks for soldiers to operate.

The design appears in Leonardo’s Codex Atlanticus and is usually dated to around 1487. It resembles a conical, covered platform mounted on wheels, with openings for a group of guns. The crew would turn cranks connected to the wheels, moving the vehicle across the battlefield while protected by armor.

It is often called Leonardo’s tank, but “tank” is a modern label rather than Leonardo’s own name. The design was never built as a working fifteenth-century military vehicle. Some modern reconstructions have also discussed a likely error in the drawing’s gear arrangement, which would make the original mechanism difficult to move without modification.

The concept is historically important because it combined mobility, protection, and firearms in one machine, anticipating features associated with later armored vehicles without being a modern tank in the engineering sense.