What Leonardo da Vinci weapon concept featured a very large bow and projectile?

Leonardo da Vinci’s giant crossbow was a weapon concept featuring an enormous bow and projectile.

Leonardo designed the machine to intimidate opponents and launch a large bolt. Its bow was arranged horizontally, and the design included a system intended to draw the bowstring back mechanically. Wheels beneath the frame were meant to help transport the weapon.

The giant crossbow was much larger than an ordinary crossbow, but size alone would not guarantee effectiveness. A massive bow requires tremendous energy to draw and a strong frame to contain the stored force. Leonardo’s design therefore focused heavily on mechanisms for loading and supporting the weapon.

Like many of Leonardo’s military projects, the giant crossbow is known from drawings rather than a surviving original. It illustrates his interest in combining spectacle, engineering, and battlefield technology.