Leonardo da Vinci designed a giant crossbow for launching heavy projectiles.
The design appears in drawings from the late fifteenth century and was intended to intimidate as well as attack. Its very large bow was mounted on a wheeled frame, while a winch mechanism helped draw the string. Leonardo’s notes suggest that the weapon was meant to fire large bolts or other heavy missiles over a substantial distance.
The machine was not a conventional hand-held crossbow. Its scale required mechanical assistance and a supporting structure, placing it closer to a siege engine. It was also not the same as a ballista, an older torsion-powered weapon that launched projectiles using twisted cords.
As with many of Leonardo’s military projects, the surviving drawings do not establish that the complete device entered battlefield service. The giant crossbow illustrates his interest in combining intimidating size, leverage, wheels, and mechanical loading systems.