What defensive vehicle did Leonardo da Vinci design in 1487?

Leonardo da Vinci designed an armored vehicle in 1487.

The machine is usually called Leonardo’s fighting vehicle or Leonardo’s tank. His drawing shows a conical, turtle-shaped cover made from reinforced wood and metal plates. Several small cannons project through openings around the vehicle, allowing weapons to fire in multiple directions.

The vehicle was intended to move with human-powered cranks connected to wheels. The armor would protect its crew from enemy fire while the sloping exterior could help deflect projectiles. Leonardo prepared the design while seeking work from Ludovico Sforza, the ruler of Milan.

The design was never built as a Renaissance battlefield vehicle. Some modern reconstructions note that the gearing shown in the drawing would make the machine difficult or impossible to drive unless corrected. It is therefore best understood as a concept for an armored combat vehicle, not the direct ancestor of a working modern tank.