Leonardo da Vinci designed an armored vehicle for military use in the 1480s called a tank. His drawing shows a conical, turtle-like cover made from wooden panels reinforced with metal plates.
The vehicle was intended to move using several pairs of wheels powered by men turning internal cranks. Its sloping armor could deflect projectiles, while openings around the base allowed cannons to fire outward. Leonardo’s surviving design is often described as an early tank concept, although it was never built for battlefield service in his lifetime.
A famous detail is that the mechanism appears to contain a deliberate gearing problem: the wheels would turn in opposite directions. Historians debate whether this was an error, a design change, or an intentional safeguard. The machine was not a modern tank, because it had no engine, but its armored, mobile gun platform resembles the basic idea later associated with tanks.