Leonardo da Vinci designed an armored fighting vehicle commonly called Leonardo's tank, with a conical cover and all-wheel drive.
Leonardo drew the vehicle around 1487–1490 while working for Ludovico Sforza in Milan. Its sloping wooden shell was intended to deflect enemy fire, while a ring of cannons projected through openings around the lower edge. The design resembles a short, covered tortoise rather than a modern tracked tank.
The vehicle was meant to be moved by people turning internal cranks connected to wheels. A commonly noted problem is that the original drawing's gearing appears to make the wheels turn in opposing directions. Some historians suggest this may have been deliberate, or simply a drafting error; the surviving design was never built in Leonardo's lifetime.
It is often described as an early tank, but it had no engine, tracks, or practical battlefield demonstration. Its importance lies in combining armor, mobility, and concentrated firepower in one Renaissance concept.