Leonardo da Vinci sketched an armored fighting vehicle that is commonly regarded as a tank precursor.
The vehicle had a conical protective shell inspired partly by a tortoise’s shape. Cannons projected through openings around the perimeter, allowing the crew to fire in several directions while remaining shielded. Leonardo’s design also included wheels and a system of gears intended to drive the vehicle.
It was a conceptual military machine, not a completed tank. Historians and engineers have noted that the surviving drawing appears to contain a gearing problem that would prevent the vehicle from moving as shown. Some researchers think the mistake may have been deliberate, since Leonardo sometimes protected military designs from unauthorized use.
Modern tanks developed centuries later and use engines, tracks, armor, and turrets. Leonardo’s vehicle lacked those technologies, but its combination of armored mobility and mounted guns explains why it is often linked with the history of tanks.