Which Leonardo da Vinci design is widely regarded as an early armored vehicle?

Leonardo da Vinci’s early armored vehicle design is known as Leonardo’s tank.

Leonardo designed the fighting vehicle around 1487–1489 while working for Ludovico Sforza in Milan. The machine had a conical, turtle-like protective shell and multiple light cannons arranged around its perimeter. A crew inside would turn crank handles connected to wheels, allowing the vehicle to move across a battlefield while shielding its occupants.

The design was never built for Renaissance warfare, and historians debate whether the famous drawing contains an intentional gearing error or a copying mistake. As drawn, the opposing wheels would rotate in incompatible directions, though the problem could be corrected by changing the gear arrangement.

Calling it a “tank” is modern terminology. Leonardo described a covered fighting vehicle, not a modern tracked tank with an engine, turret, and armor system.