Leonardo da Vinci designed a giant crossbow mounted on a wheeled platform. He sketched the weapon around 1493–1494 as a siege device intended to launch large bolts or stones.
The design used a very broad bow made from flexible material, with the bow mounted horizontally on a carriage. Leonardo’s drawing includes a mechanism for drawing the string and a platform that could help position the weapon. Its imposing size was meant to create both destructive power and psychological impact.
The giant crossbow is sometimes confused with Leonardo’s multi-barrel artillery designs. Those weapons use gunpowder and barrels, while the giant crossbow is a tension-powered projectile weapon. It also differs from a classical ballista, although both rely on stored mechanical energy to propel missiles.
There is no firm evidence that Leonardo’s giant crossbow was completed as a successful battlefield weapon. Like many of his military sketches, it demonstrates his interest in scaling familiar mechanisms into ambitious machines.