Who invented the first trebuchet?

There are varying accounts regarding the inventor of the first trebuchet. It is said that the French army introduced the medieval weapon in the 12th century. Others claim that the trebuchet was a Chinese creation made around 300 B.C.

A trebuchet was a mechanical siege weapon, similar to a catapult, that hurled a projectile placed inside a sling and then attached at the end of a long beam. The trebuchet was propelled by a downward force, which came from the people pulling down the shorter end of the beam to flip the longer end. The design of the trebuchet was later improved to include a counterweight. Castles and stone fortifications were defenseless against the destructive power of the trebuchet.