Ancient Mongolian Seige Machines
The ancient Mongolians used seige machines to either knock down walls or to throw things over them and any other ways to get into an enemy city. The Mongolian got most of their ideas of seige machines from captured mechanics from different civilizations. The seige machines could be disassembled and transported on horseback.
The Mongols used the catapult to launch many different things over enemy walls. Sometimes the catapults would be used to throw the bodies of plauge victims in to the city. This would cause the disease to spread inside the city and allow it to be captured easily. The catapukt would also launch rocks to try to knock down walls.
The trebuchet was a more high-tech version of the catapult. It could launch heavier projectiles farther than the regular catapult could. It was also more accurate and was used more to destroy walls than it was to throw things over them. The trebuchet launched rocks of 1,500 kg and also launched flaming items.
A mangonel was used to throw items like rocks ar enemy walls. The accuracy of a mangonel was not as good as the trebuchet, but it threw items harder than it did. The mangonel was used for knocking down walls, not for throwing items over or for killing enemy troops. It could also throw burning objects like fire pots.