Leonardo da Vinci designed a tank as an armored vehicle powered by people inside it.
In about 1487, Leonardo drew a conical, turtle-shaped fighting vehicle with sloping armor plates. The covering was intended to deflect incoming projectiles, while several light cannons projected through openings around the vehicle. Cranks and gears connected to wheels were supposed to let operators move it across the battlefield.
The design is often called Leonardo’s fighting vehicle rather than a fully workable tank. Historians have identified problems in the gearing and in the number of people needed to operate it. Some researchers have suggested that one apparent flaw may have been deliberate, because Leonardo was presenting military ideas to Ludovico Sforza and may have wanted to protect the design.
Modern tanks use engines, tracks, rotating turrets, and advanced armor. Leonardo’s vehicle had none of those features, but its enclosed armored body and onboard weapons explain why it is commonly described as an early tank concept.