What is a siege?
A siege is when you and your army surrounds a castle or a town and take their resources, and take over the castle.
One of the weapons in the middle ages were the ballista, a ballista was like a giant crossbow used in the middle ages. The ballista was used for weakening walls and damaging the castle.
The ballista hurled large bolts for their ammo, the ballista was used mostly on sieges. The ballista worked by the use of tension the ballista is more accurate than a catapult but it had reduced range. The ballista was developed in 399 BC.