Leonardo da Vinci designed a giant crossbow mounted on wheels and equipped with a winding mechanism.
The enormous bow was intended to launch large bolts or stones and to intimidate an opponent as much as to deliver a projectile. Leonardo’s design included a broad frame, wheels for movement, and a mechanical system to draw the bowstring back, since a person could not easily perform that task alone.
The weapon belongs to Leonardo’s late-fifteenth-century studies of military engineering. It was a design proposal rather than a proven battlefield weapon, and there is no reliable evidence that Leonardo’s exact machine entered regular service.
The giant crossbow is sometimes confused with the ancient ballista, which was also a large projectile weapon. The distinction is that Leonardo’s design is specifically a wheeled, mechanically drawn crossbow. It illustrates his habit of enlarging familiar mechanisms and combining them with transport and loading systems.