Counterweight Trebuchet

Timeline

1. c. 1000–1120Islamic world and Byzantine frontier · Western AsiaThe counterweight trebuchet may have been standardized in the Islamic world in the 11th century, replacing torsion bundles with counterweight boxes and greatly enhancing throwing power, spreading east and west along trade routes and channels of military contact.
2. c. 1121–1126Levant castle siege battlefields · LevantCrusaders and Muslims alike used large trebuchets to bombard walls and inner keeps when besieging fortresses such as Kerak; the counterweight design allowed continuous firing of heavy stones, making it standard siege equipment of the 1120s.
3. c. 1127–1130Anatolia and Syria · AnatoliaDefenders responded with deep ditches, earth cover, and anti-trebuchet positions, while attackers increased counterweights and arm lengths to extend range; this arms race drove further refinement of trebuchet engineering by the late 1120s.