Leonardo da Vinci designed a giant crossbow as a wheeled military weapon.
The design appears in Leonardo’s military engineering studies from the late 15th century. Its enormous bow was intended to launch large bolts or stones, while wheels and a mechanism for drawing the bow were meant to make the weapon manageable in the field.
The crossbow was probably more a conceptual engineering project than a successfully deployed battlefield weapon. Leonardo emphasized scale, leverage, and mechanical force, all recurring themes in his notebooks. The design is sometimes confused with his giant catapult studies, but the two weapons used different launching mechanisms.
Leonardo’s drawings do not prove that a working example was built. They show how Renaissance engineers combined practical military needs with experimentation in mechanics and construction.