Leonardo da Vinci’s proposed armored vehicle is commonly compared with a tank.
Leonardo designed the fighting vehicle around 1487–1490 while working in Milan. His drawing shows a conical, armored shell mounted on wheels, with openings for guns around its circumference. Several men inside would turn cranks to drive the vehicle and operate its weapons.
The machine was intended as a mobile platform for a battlefield, not as a modern tracked tank. Its armor and gun arrangement explain the comparison, but its propulsion system would have been difficult to use, and the design was never built as a practical Renaissance weapon.
A famous modern claim says Leonardo deliberately inserted a flaw so the vehicle could not work. The reverse gearing may instead reflect a drawing error, an unresolved engineering problem, or incomplete design. In either case, the surviving plan is a concept rather than proof of a working tank.