What type of protective vehicle did Leonardo da Vinci design for warfare?

Leonardo da Vinci designed an armored tank for warfare.

Leonardo’s fighting vehicle appears in a drawing from about 1487. It resembles a conical, armored shell mounted on wheels, with openings for cannons around its circumference. The design was intended to advance toward an enemy while protecting the people inside from small-arms fire.

The vehicle was powered by a system of cranks and gears operated by its occupants. A famous flaw in the surviving drawing makes the gears appear arranged so that the vehicle would move backward. Some historians think this was a deliberate error to keep the design from being used, while others consider it a drafting mistake or an unresolved engineering problem.

Calling it a “tank” is convenient modern terminology. Leonardo did not use that English word, and his machine was never built as a battlefield vehicle in his lifetime. It remains one of the best-known examples of his interest in combining mechanical engineering, armor, and artillery.