The earliest writings of catapults were originated in China around the 3rd and 4th Century BC and this type of catapult was much like a big crossbow (E. W. Marsden). They stood around 8 feet tall. We usually think of a catapult as something that was used in the Middle Ages to destroy the walls of a castle. But catapults have a very long history dating long before the time of castles and they were developed in many different ways over the centuries. The general definition is that a catapult is a machine that stores energy then quickly releases the energy to fire a projectile. The basic parts of a catapult are the counterbalance, the fulcrum, the arm, and the sling. Each of these parts interacts with one another in order to propel the arm forward and launch the projectile. (“Catapults” Wikipedia)
The oldest catapults were Ballistas. They were giant crossbows although they were deadly accurate; ballistas weren't too effective weapons, as they lacked the serious muscle power needed to knock down the enemy walls. Also, their limited mobility was another inconvenience during war times, and they were often put together at the battlefield. These were widely used by the Romans and the Greeks towards the end of the third century. (E. W. Marsden)
Springald was an adaptation of the original ballista, the springald was believed to have originated in the Middle East. As opposed to other catapults, this was mainly used in a defensive role, within a fort rather than on the battlefield. It was not as powerful and was mainly used as an anti-personnel weapon at close range. It was mostly installed on the top of castles to ward off the enemies. As it wasn't the most efficient of catapults, its use was restricted to a much smaller region.
Mangonels were a more powerful adaptation of the catapult in the 12th century. The name was derived from the Latin word manganon, which means 'engine of war'. The design of the original ballista was modified, and the new machine was...