Trebuchet

The trebuchet is a siege engine that uses a pivoting arm to hurl heavy projectiles, either by human traction or by a heavy counterweight. Traction trebuchets were widely used in Chinese warfare, including by the Song Dynasty. During the Mongol siege of Xiangyang, the Yuan Dynasty deployed counterweight trebuchets built by engineers from the Islamic world, helping to break the city's long resistance in 1273.