What armored Leonardo da Vinci design used a conical shell and many cannons for battlefield movement?

Leonardo da Vinci's fighting vehicle was an armored, conical vehicle designed to move across a battlefield while carrying multiple cannons.

Leonardo drew the vehicle around 1487 for Ludovico Sforza, the Duke of Milan. Its sloped armor was intended to deflect incoming weapons, while guns arranged around the platform could fire in several directions. Inside, men would turn cranks connected to wheels, although the original gear arrangement would not have made the vehicle move as drawn.

The design is often called Leonardo's tank because it resembles a modern armored fighting vehicle. That label is retrospective: tanks developed much later and used engines, tracks, and different weapons. Some historians have suggested that the apparent gear problem may have been deliberate, because Leonardo was presenting a military idea to a patron rather than a fully buildable machine.