Leonardo da Vinci’s armored tank was a covered, circular fighting vehicle with guns around its sides.
Leonardo drew the machine in 1487 for the ruler Ludovico Sforza of Milan. Its conical cover resembled a tortoise shell and was intended to protect soldiers from enemy fire. Small cannons projected through openings around the perimeter, while men inside would turn cranks connected to the wheels.
The design was never built for Renaissance warfare. Its armor would have made the vehicle extremely heavy, and a commonly noted problem is that the gearing shown in the drawing would make the wheels turn in the wrong direction. Historians debate whether this was an intentional flaw to keep the design from being copied or simply a drafting error.
The machine is often called Leonardo’s tank, but it was not a modern tank: it had no engine, tracks, turret, or reliable independent mobility. It remains one of the best-known examples of Leonardo’s military engineering imagination.