What Leonardo da Vinci war machine was a covered vehicle equipped with multiple guns?

Leonardo da Vinci’s armored tank was a covered vehicle equipped with multiple guns. He designed the fighting vehicle around 1487–1489 for the Duke of Milan, presenting it as a mobile platform that could approach enemy forces while protecting its crew.

The machine had a conical, turtle-like shell made from wooden plates reinforced with metal. Cannons were arranged around the perimeter so they could fire in several directions. Inside, men would turn cranks connected to wheels, although the surviving design appears to contain a gearing problem that would make the vehicle move backward if built exactly as drawn.

The vehicle was never produced for Renaissance warfare. It is often called a tank because of its protective shape, but it had no engine, turret or modern armored-vehicle technology. The design shows Leonardo combining battlefield protection, artillery and coordinated mechanical motion in one ambitious machine.