Leonardo da Vinci's machine with an armored conical shell was an armored vehicle.
Leonardo designed the fighting vehicle around 1487–1490. Its sloped, conical covering was intended to protect people inside from enemy fire, while a ring of light cannons could fire through openings around the perimeter. The vehicle was to be moved by cranks connected to internal wheels.
The design is often called a tank because its protective shell and weaponry resemble later armored fighting vehicles. However, it was not a modern tank: it had no engine, tracks, or demonstrated battlefield performance. A well-known issue in the drawing is that the gear arrangement would make the vehicle difficult or impossible to drive as shown, although some historians think this may have been deliberate or may reflect an error in the surviving plan.
Leonardo's proposal combined armor, mobility, and all-around firepower in one machine, making it an important early concept in the history of armored vehicles.