Leonardo da Vinci’s armored fighting vehicle concept is commonly called Leonardo’s tank.
Leonardo designed the fighting vehicle around 1487 for Ludovico Sforza, the ruler of Milan. Its conical, turtle-like shell was made from wooden plates reinforced with metal. Cannons were arranged around the platform so the crew could fire in multiple directions while protected by armor.
The vehicle was intended to move using cranks connected to wheels. However, the surviving drawing contains a mechanical problem: if the gears are followed literally, the wheels would turn in opposing directions. Historians have debated whether this was an error, a deliberate flaw, or a copying issue in the manuscript.
It was never built as a battlefield vehicle in Leonardo’s lifetime. The design is called a tank because its armored, weapon-carrying form resembles later tanks, but it did not use an engine, tracks, or modern tank technology.