What type of vehicle did Leonardo da Vinci sketch with sloped armor and a circular platform?

Leonardo da Vinci sketched an armored vehicle with sloped armor and a circular platform.

The design appears in Leonardo’s notebooks from the late fifteenth century. It resembles a large, covered wagon with conical armor plates intended to deflect incoming projectiles. A group of men inside would turn cranks connected to the wheels, allowing the vehicle to advance across a battlefield.

The machine is commonly nicknamed Leonardo’s tank, but “armored vehicle” is a more precise description of the surviving concept. It was never built for Leonardo’s patrons, and its practical operation has been debated. One famous drawing appears to contain a gear arrangement that would make the vehicle move backward rather than forward if built exactly as shown.

Some historians think that apparent flaw may have been deliberate, because Leonardo sometimes concealed military details in presentation drawings. The design demonstrates his interest in combining protection, mobility, and concentrated firepower.