One of the most iconic images of the European Middle Ages is the castle. This defensive structure was often heavily fortified and provided its inhabitants with much-needed safety. It was usually quite difficult for an enemy to capture a castle, and for that, an attacking army needed siege engines. The catapult was one of the most efficient of these war machines.
The Roman Onager
The catapult was a weapon used since ancient times. In its most basic form, the catapult may be described as a “one-armed stone thrower”. In the Roman world, a catapult-like siege engine known as the ‘onager’ (meaning ‘wild ass’) was used when the Romans were besieging an enemy. One suggestion for this name’s origins is that the Romans likened the stones that were hurled by the catapult to the rocks kicked up behind galloping hooves.
An alternate suggestion is that the device jumped when it fired its projectiles. Another type of catapult, which had a sling, was known as the ‘scorpion’, as a shot from this device is reported to resemble the movement of a scorpion’s tail.
Chinese Traction Catapults
The use of catapults, however, was not limited to the Roman army. There are records which show that the catapult was also employed by the armies of ancient China as well. For example, during the early Spring and Autumn period (8th – 7th centuries BC), there was a machine called a ‘hui’ that was used by the King of Zhou against the Duke of Zheng during a battle in 707 BC. As the word ‘hui’ no longer exists, we cannot be completely sure of its meaning. Nevertheless, scholars from the Han Dynasty interpreted this device as a catapult.
A clearer mention of the catapult in Chinese sources may be found in the Mohist texts of the Warring States period (5th – 3rd centuries BC). In these texts, the catapults were operated using the lever principle, and are known as traction catapults. These devices could be used by either the besieger or the besieged. As a weapon employed by the besieged, the traction catapult could be used to attack enemy siege towers, and to hurl objects at enemy troops either to kill them or to disrupt their formation.
The Torsion Catapults
In the West, by contrast, catapults operated according to a different principle. Instead of using the lever technique, European catapults operated according to torsion mechanics. This technology was first introduced by the Greeks, and later adopted by the Romans.
By the European Middle Ages, a variation of the Roman ‘onager’ was developed. This was called the mangonel, which means ‘an engine of war’ (mangonel may also refer to other siege engines). The primary difference between an ‘onager’ and a mangonel is that the latter launched its projectiles from a fixed bowl rather than from a sling. This meant that instead of a large, single projectile, the mangonel could be used also to launch a few smaller projectiles.
Traction Meets Torsion
Whilst torsion-operated catapults were being used by European armies, Chinese traction catapult technology had also spread westwards during and around the 6th century AD. It has been speculated that the knowledge of this technology was partially responsible for the victories achieved by the Islamic armies over the next few centuries.
Nevertheless, the first recorded Western encounter with the traction catapult was not during a battle with a Muslim army, but with a nomadic tribe known as the Avars. According to John, an Archbishop of Thessaloniki, during the siege of the city in 597 AD, the Avars were using 50 large traction catapults that hurled stones at the defenders.
It has been speculated that the Avars had interacted with the Northern Wei in China, and learned the traction catapult technology from them. European encounters with the traction catapults of the Muslims (commonly known as ‘al-manjaniq’) would only come later during the Islamic conquest of Iberia. However, it has been argued that it was only during the Crusades that such technology became adopted in Europe.
The Evolution of the Trebuchet
The catapult eventually evolved into the hinged counter-weight trebuchet, a siege engine that had much greater accuracy and range, as well as a higher trajectory than the catapult. Whilst the trebuchet dominated the European battlefield for several centuries, it soon became obsolete in China due to the introduction of gunpowder weapons.
The arrival of gunpowder in Europe also signaled the end of the widespread use of these siege engines. However, the last major use of catapults in battle is said to have happened during the First World War, when French troops used these devices to hurl grenades into German trenches.