Leonardo da Vinci’s armored military vehicle is commonly called his fighting vehicle.
Leonardo designed it in the late 15th century while seeking military commissions. The machine had a conical, armored shell inspired partly by a tortoise’s protective shape. It was intended to carry weapons and provide shelter for soldiers while moving across a battlefield.
The vehicle’s drawings show wheels and internal mechanisms operated by people inside. A famous issue is that the gearing in the surviving design appears to prevent the vehicle from moving as intended. Some historians and engineers have suggested that this may have been an error, while others have wondered whether Leonardo deliberately concealed a flaw from potential military clients.
The concept was not a modern tank, because it had no engine, tracked system, or demonstrated battlefield use. Nevertheless, its armored enclosure and integrated weapons make it an important early example of a proposed armored fighting vehicle.