Leonardo da Vinci’s giant crossbow design was mainly intended to create fear.
Leonardo designed the giant crossbow during his service to Ludovico Sforza in Milan. The weapon was enormous, with a bow mounted on a broad frame and wheels intended to help move it. Leonardo’s notes and presentation emphasized its impressive scale and psychological impact as much as its ability to launch a missile.
The design belonged to a period when military patrons valued both practical engineering and intimidating spectacle. A very large weapon could signal power, even if its battlefield usefulness was limited. Leonardo’s crossbow was never known to have been built or used in combat.
It is sometimes confused with a catapult because both belong to the family of ancient and Renaissance siege concepts. A crossbow stores energy in a bent bow and releases it through a string; a catapult uses a different throwing mechanism. Leonardo’s design remained a drawing and proposal.