Leonardo da Vinci sketched an armored fighting vehicle that is often called an early tank design.
The vehicle resembles a conical, turtle-like cover mounted on a wheeled platform. Its sloped armor was intended to deflect incoming fire, while several small cannons projected through openings around the structure. Leonardo’s notes also included a system of gears and cranks for moving the vehicle.
This was a concept, not an operational tank. The proposed vehicle would have been extremely heavy, and its mechanical arrangement appears unable to move as drawn unless the gearing were corrected. Some historians think the apparent flaw may have been deliberate, because Leonardo may have wanted to conceal the design from unauthorized readers.
Modern tanks developed much later, especially during the First World War. Leonardo’s vehicle is therefore best described as a Renaissance armored-vehicle concept rather than the first modern tank.