Leonardo da Vinci’s giant crossbow design featured a huge bow mounted on a wheeled platform.
Leonardo drew the weapon around 1488–1489, during his service to Ludovico Sforza in Milan. The design enlarged the ordinary crossbow dramatically, using a broad wooden frame, wheels, and a winding mechanism to draw the bowstring. Its size was intended to increase range and psychological impact rather than make it a practical battlefield weapon.
The drawing shows a flexible bow mounted across a long platform, with a central mechanism for pulling back the string. Historians generally regard it as a concept rather than a completed weapon. Leonardo’s military notebooks often combined engineering analysis with theatrical presentation for a prospective patron.
This design is different from Leonardo’s multiple-barrel gun, which used repeated small cannon barrels, and from his armored vehicle, whose body was conical. The giant crossbow is identified by its exceptionally large bow and wheeled support.