Author Archives: caltrop101

The Trebuchet in Medieval Warfare

by caltrop101

The Trebuchet: A General Idea

The concept of the trebuchet is a simple one, almost entirely based on simple machines. A sling is attached to one end of a lever, with force applied to the other end and a pivot in the middle. A lever allows forces to be multiplied by altering the distance that force is applied through, so a small force applied over a large distance can replace a large force. Alternatively, a large force applied through a small distance can be converted into a small force applied over a large distance. It is this latter case that a trebuchet makes use of, using a large force to move a small object through a large distance (and at high velocity).

Over Time

This general concept was consistent throughout the trebuchet’s history. The main point of development was the process by which the large force was applied to one end of the lever to produce the rapid motion of the other end. The most powerful version of this is the counterweight trebuchet, where potential energy is stored in a large mass, raised off the ground. When this mass is allowed to swing, its potential energy is transferred to the projectile as kinetic energy.

The original trebuchet was what is now known as the “traction trebuchet.” This trebuchet used people hanging from ropes as a counterweight. However, as there are only so many people you can fit under a trebuchet, this setup had natural limitations in the size and speed at which it could launch a projectile. By introducing a self-contained counterweight, significantly more force could be applied to the lever, at the sacrifice of some firing speed (it takes longer to reload a counterweight trebuchet than it does for a large group of people to stand up). This allowed for a more efficient system in several other ways, most notably positioning the projectile in the sling closer to the pivot for a more efficient motion, as well as other innovations such as the swinging counterweight.


A Byzantine Traction Trebuchet


A Mongol Counterweight Trebuchet. Note the hinged counterweight for greater efficiency.

Comparison: Catapults

In trying to understand the value of the trebuchet, it is helpful to compare it with another well-known siege weapon: the catapult. The primary goal of both is the same: to launch heavy and deadly projectiles at structures/troops or over fortifications. However, the similarities basically end there. While the trebuchet stores the projectile’s energy by means of raising a large mass, a catapult is powered by torsion—energy stored by the deforming of rigid objects. This is usually done in the form of bending wood, twisting ropes or sinews, or both.

There are some natural advantages to the trebuchet. It is much simpler, mechanically, making it far easier to build, and its motion puts much less strain on the pieces of the engine, allowing for larger amounts of energy to be stored than a catapult can handle, and, as a result, larger projectiles can be launched. It is also far less susceptible to rain, humidity, or damage to small elements of the system causing the whole thing to fly apart violently. There are a few downsides, of course, such as the size of the trebuchet making it an easier target, as well as its general immobility, but in warfare the amount of damage a trebuchet is capable of above and beyond what a catapult can achieve certainly makes up for it.

My Trebuchet

I tried to focus on what a full-scale trebuchet would need in building mine. The launch is controlled by a small “finger” at the end of the throwing arm, at an angle to the arm. When the sling reaches a certain angle with this finger, the finger will no longer be able to hold the sling, releasing the sling and its payload. The pully system (image 2 below) for drawing the arm back down would be attached to a team of horses on a real trebuchet, who would pull the arm down to where it could be locked into place (image 3), at which point they would be unhitched from the system, the sling would be loaded, and the trebuchet would fire.

Works Cited:

  • Chevedden, Paul E., Les Eigenbrod, Vernard Foley, and Werner Soedel. “The Trebuchet.” Scientific American273, no. 1 (1995): 66-71.
  • Hacker, Barton C. “Greek Catapults and Catapult Technology: Science, Technology, and War in the Ancient World.” Technology and Culture9, no. 1 (1968): 34-50. doi:10.2307/3102042.
  • Chevedden, Paul E. “The Invention of the Counterweight Trebuchet: A Study in Cultural Diffusion.” Dumbarton Oaks Papers54 (2000): 71-116. doi:10.2307/1291833.
  • Renatus, Publius F. V. De re militari. c. 400 A.D.
  • “The Lever.” Hyperphysics. (December 1, 2018).
  • “Trebuchet.” Wikipedia. (December 1, 2018).

Picture Credit:

Leave a comment

Filed under Uncategorized

Historical Analysis: Bayeux Tapestry #67

This post will analyze the 67th panel of the Bayeux Tapestry (as numbered in Wilson, David M. The Bayeux Tapestry), looking for what it teaches us historically and what we can glean artistically from it. The Bayeux Tapestry is an artistic depiction of Duke William of Normandy’s invasion of Britain in 1066, with special emphasis given to the Battle of Hastings, October 14, 1066. Throughout the tapestry, William’s Norman forces are represented in chainmail, whereas the British fighters are usually shown without any armor to note. This conflict took place either (a.) because this was the middle ages and rulers back then really didn’t have anything better to do with their time, or (b.) because the death of King Edward left something of a power vacuum that William and several other claimants tried to fill. As later generations have dubbed Duke William “the Conqueror,” it isn’t hard to guess who was most successful in this effort.

This panel specifically bears the caption “HIC ODO EPISCOPUS BACULUM TENENS CONFORTAT PUEROS,” which translates as “Here Bishop Odo, with a staff in hand, encourages his squires (literally “boys”).” Bishop Odo was Duke William’s half brother, and as such a prominent character in this panel he will receive special attention here. We will also observe the borders and the general scene in the tapestry.

Bishop Odo of Bayeux:

His outfit makes him stand out from the other soldiers, highlighting him as a prominent figure in a way that even his brother William in the next panel doesn’t get (Duke William is consistently depicted in chainmail, like all of his troops). It is implied that Odo is wearing at least some chainmail by the avantail–“mail protection for the neck, which hangs down from the helmet”–one can see dangling from his helmet. It isn’t clear whether this outfit is an adornment worn on top of his actual armor (as a bishop it wouldn’t be surprising to see him with at least somewhat different adornment) or if he is actually wearing a different type of armor (this could be a simplistic representation of scale mail, though having one person in the whole army wearing a very different type of armor would be surprising). As Bishop Odo was very possibly the one who commissioned the tapestry, it wouldn’t be surprising if he simply did this to make his presence in the tapestry more apparent.

Another distinguishing feature of Bishop Odo is the club he is carrying, in similar fashion to his brother Duke William’s chosen weapon. This is actually somewhat historically interesting, as it gives potential insight into the culture of the time. This is actually a fairly strong indication that the leadership in the army imitated their commander, either to impress said leader or to stand out from common troops as a “badge of rank”. This detail has a certain ring of truth that makes it seem more historical than artistic.

Lastly, many historians have noted how this panel of the tapestry emphasizes the fact that Odo, likely due to his clerical status, did not “fight” per se, but directed and encouraged his troops from the back.


The top border is likely wholly decorative in this portion, unless there was in fact a bird trying to bite its own toe at Hastings. The bottom border is a little more informative. Though it was likely included primarily as decoration, and though one corpse is much the same as another in essentials (at least, inasmuch as one can pretty easily imagine what a corpse of one of the soldiers would look like by seeing the depictions of the soldiers), the bottom tapestry does give good depictions of weaponry, armor, and a horse’s tack, all unobstructed by other elements. Admittedly, however, not much historical information can be gained from these, on account of the oversimplification necessary in representing these things via embroidery.

General Scene:

The bulk of this scene is, as its heading describes, a number of Norman soldiers on horseback being urged on by Bishop Odo. There are a few englishmen depicted on the left making some very expressive facial and hand gestures. This panel shows an interesting art style in which two scenes are overlaid by intermingling their subjects in an overlapping fashion, making it somewhat jumbled and disorganized. This image would seem to indicate that the Norman knights, a previously unfamiliar foe for the english, favored the broadsword or the lance, while the British seemed to prefer the spear or javelin.


Works Cited:

Vitalis, Orderic. “Historia Ecclesiastica.” Translation by Forester, Thomas, 1853. Accessed on November 25, 2018,

Wilson, David M. The Bayeux Tapestry. Thames & Hudson, 2004.

Prestwich, Michael. Knight: The Medieval Warrior’s (Unofficial) Manual. Thames & Hudson, 2010.

“The History of Britain’s Bayeux Tapestry.” Britain’s Bayeux Tapestry at Reading Museum. November 20, 2018.

“The Weaponry of 1066.” English Heritage. November 20, 2018.

Picture Credit: (Unfortunately, I could not figure out how to get the photos to upload)

Wilson, David M.

Leave a comment

Filed under Uncategorized