Answer:
Prior to 1268, the counterweight trebuchet may have been used in 1232 by the Jurchen Jin commander Qiang Shen. Qiang invented a device called the "Arresting Trebuchet" which only needed a few men to work it, and could hurl great stones more than a hundred paces, further than even the strongest traction trebuchet.
Answer: It was invented by Mariano Taccola, "The Sienese Archimedes"
but historical records say it was invented by a Chinese military engineer named Ch'in Kung.
