Leonardo da Vinci sketched a giant crossbow mounted on a wheeled firing platform.
The design appears in Leonardo’s military engineering studies from the late fifteenth century. Its enormous bow was supported by a broad frame, and wheels were included to help move the weapon. A winch or similar mechanism would have been needed to draw the powerful bowstring before firing a large bolt or stone-like projectile.
Leonardo’s purpose was likely both practical and presentational. A huge crossbow could project force at a distance, while its scale would also impress a prospective military patron. The surviving drawings emphasize proportions and mechanisms, but they do not establish that the weapon was completed or used successfully in battle.
The giant crossbow is sometimes mixed up with Leonardo’s giant crossbow-like designs for artillery. A crossbow stores energy by bending a bow, whereas a cannon stores energy through the rapid expansion of burning gunpowder.