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  • Writer's pictureChristopher Riley

Weapons That Changed The World: The Counterweight Trebuchet

Updated: Sep 16, 2020

The word Trebuchet comes from the old French 'Trebucher' meaning 'to throw over', and that is exactly what medieval siege weapons like trebuchets were designed to do. Used to hurl giant stones or boulders (see image below) directly at the walls of castles or fortifications or, simply to throw disease ridden bodies or other unpleasantries over the walls, to sap moral and infect the inhabitants waiting inside. Ether way the trebuchet became an essential part of a medieval sieges, and turning up without one was like forgetting to put your trousers on in the morning!

A contemporary image of a trebuchet being loaded SOURCE:

Where did they come from?

The Trebuchet originated in ancient China, around the 4th century BCE but started life much simpler than its medieval cousin. The traction Trebuchet or Mangonel, which was adopted by the Byzantine empire some 100 years after their first recoded use in China, relying on man power to pull ropes and weights to thrown the projectile via the long swinging arm, a very time consuming and some what inconstant tool.

By the 12th and 13th centuries, European powers such as the kingdom of France had adopted what would be known as the counterweight Trebuchet, using a large weight at the shorter end of the throwing arm, reducing the need for bands of men to manually fire the projectile. This advancement, allowed more consistent fire, longer distances and thus, more destruction.

Image from an illuminated manuscript depicting a Byzantine traction trebuchet at a siege of a citadel, 11th century. SOURCE: Skylitzes chronicle, Madrid, National library via

How did they work?

Medieval trebuchets were made up of a large triangular base, allowing the large arm to swing a full 360 degrees around, so it could be loaded and fired without the risk of it smashing into its self. Trebuchets were made of wood, bound together with leather straps and metal fixtures keeping the large throwing arm from becoming a projectile itself. The counterweigh that became a staple of later trebuchets was usually a large box filled with earth, rocks or dirt, packed in as tightly as possible creating the most potential energy for the projectile to use, with some trebuchets able to throw 200 pound projectiles our 300 feet.

the design and manufacturing of trebuchets changed little, once the counterweight had been added to the design, the overall look and effectiveness of the weapon varied little between time periods and the people using them. Larger trebuchets would have large 'hamster' style wheels on the side of them, allowing men to run inside them to winch down the large arm where the projectile would be added, a pin would then be removed throwing the large arm upwards,

forcing the projectile out of the leather bag and onto the target.

What did they throw?

An easier way to answer this is 'what didn't they throw'. The trebuchet quickly became the ‘Royal Mail’ of siege weapons, delivering virtually anything that would fit in its large leather pouch, from the afore mentioned large rocks to pile of dung or dead and decaying bodies, to scare and mentally beat an enemy. One fascinating rumoured example of bodies being used comes from the siege of Kaffa, where in 1347, the plague ridden Mongols outside of the city started to fling over their dead and dying soldiers into the city in a hope that the smell alone, rumoured to be particular foul, would destroy the moral of the defenders calling for their surrender. Regardless of wether this specific event took place, bodies or at least body parts were used to ruin the days of besieged peoples, leading sometimes to mass outbreaks of diseases, wiping out entire cities without the attackers ever storming the walls.

A neat pile of stone ball trebuchet ammunition recovered from the moat at Pevensey Castle SOURCE: via Michael Garlick (Copyright)


All weapons have their pros and cons with the trebuchet having its fair share of both. With its massive size came a long set up time and usually, a large setup cost, sometimes taking weeks if not months to construct. Medieval trebuchets took many master craftsmen money and material to build, allowing defending forces to build their own countermeasures or, simply escape the deadly range and power of the trebuchet.

another potential negative for the trebuchet is its immovability. The much smaller catapults used at the time were nowhere near as powerful but, not requiring contacting with the earth (to generate its power) was able to be put on wheels and move to where it was needed, unlike the trebuchets that were built on the location that they were needed and would need to be deconstructed before being moved.

The War Wolf

One of the most famous examples of a trebuchet is that which was used at the siege of Sterling Castle in 1304. Edward I of England, who had spent months battering the walls of the castle with massive stone and lead projectiles, was becoming sick of the siege going nowhere. Edward called upon his master castle builder, James of St. George to oversee to construction of a massive trebuchet that would be able to hurl 300 pound projectiles at the walls. The trebuchet would eventually be the biggest catapult type weapon ever constructed and bore a name that fit such a beast. Edward’s ‘War Wolf’ was probably the largest structure most of his men had even seen outside of castles themselves and when the Scottish defenders saw the weapon of mass destruction, they quickly surrendered.

It is rumoured that Edward was so keen on trying out his new toy that he ordered the recently surrendered Scots back into the castle, quoted to have said "You do not deserve any grace, but must surrender to my will" and to prepare to feel the full might of the English crown, in the form of a bombardment from War Wolf. Building a large gallery for him and his entourage to watch the destruction from, he had the trebuchet fired and the walls quickly turned to rubble showing just how terrifying and Ferocious both the king and his massive weapon was.

A modern scale model of War Wolf showing the large wheels which men would run in to pull the large arm down ready for loading SOURCE: Ron L. Toms Via

The actual size of War Wolf is unknown but, we do know that once dissembled, the parts fit into over 30 wagons and modern estimates have the massive structure at over 300 feet tall. The sheer size and potential destructive force, forced a well supplied garrison to give up on an incredibly important castle, showing just how dangerous trebuchets could be.

The Introduction of gunpowder

Trebuchets were still being used well into the 16 century CE, even though gunpowder weapons had been fairly common on European battle fields for around 100 years. One of the last recoded uses being in 1521 at siege of the Aztec capital Tenochtitlán by the Conquistador Hernán Cortés, where gunpowder was extremely limited which forced the Spanish forces to use more 'primitive' techniques.

As with the longbow, the time of the trebuchet was cut short by the introduction of both handheld fire arms and large wall destroying cannons, ushering in a new age of death and destruction. The trebuchet is the hallmark of medieval siege warfare and is synonymous

with European battles from England to the balkans. In use for almost 1000 years, the medieval version of the Chinese trebuchet transformed the battlefield thus changing the world forever.

I hope you enjoyed this and would love to hear what you think, please leave me a comment and follow me on Instagram @chrisriley_ for more medieval history!

As always, thanks for Reading.

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