What Leonardo da Vinci armored vehicle was powered by eight men turning cranks?

Leonardo da Vinci’s fighting vehicle was an armored, turtle-shaped war machine driven by cranks and gears.

Leonardo designed it around 1487 for Ludovico Sforza, who ruled Milan. The conical armored cover was intended to protect occupants from enemy fire, while cannons placed around the perimeter could fire in several directions. Inside, a system of gears connected hand cranks to the wheels.

The surviving drawing appears to contain a deliberate flaw: the gears would make the wheels rotate in conflicting directions. Historians debate whether this was a drafting error, a copying issue, or an intentional safeguard to prevent the design from being used. The vehicle was never built in Leonardo’s lifetime.

Calling it a “tank” is convenient but historically imprecise. Modern tanks use engines, tracks, armor systems, and military doctrines that did not exist in Renaissance Italy. Leonardo’s design was an armored gun carriage concept, not a working modern tank.