Skip to main content

The Medieval Siege: How to Make a Castle Crumble

Matthew's interests include writing, gaming, movies, and pretending to be Irish despite only having one Irish Great Grandparent.

Read on to learn all about the importance of castles and the methods and weapons of castle siege in the Middle Ages. Pictured above is the Siege of Lisbon in 1147.

Read on to learn all about the importance of castles and the methods and weapons of castle siege in the Middle Ages. Pictured above is the Siege of Lisbon in 1147.

The Importance of Castles

Castles were the technological revolution that ended the dark ages and ushered in the feudal era. The rampant pillaging by barbarian hordes was brought to an abrupt halt by these sturdy structures, which became bastions of military might.

Many of them were placed at key strategic points, thereby granting control over the land for miles around. This made the taking of castles pivotal to any military campaign.

Of course, taking a castle was difficult, hence why they were so valuable in the first place. The art of conducting a siege was a key skill set for any medieval military commander.

Siege is a French word meaning "sitting", and while it did indeed involve "sitting" your army outside the enemy castle, letting your guard down was certainly not an option. Close your eyes for a second, and the defending army would smuggle in some critical supplies or evacuate an important individual right under your nose.

Sieges have a long history. This Assyrian relief, which dates back to 730 BC, depicts an attack on an enemy city.

Sieges have a long history. This Assyrian relief, which dates back to 730 BC, depicts an attack on an enemy city.

Castle Defences

To fully appreciate the challenge facing a besieging army, let's first assess the obstacles in their path.

Castle defences usually included:

  • A motte and bailey. Castes in France and England adopted this basic design around the 11th century. It consists of a wooden tower on a mound (motte) above a walled courtyard (bailey).
  • Ditch. It may not sound like much, but this was a simple yet effective defence. A ditch made it difficult for the attacking army to move siege equipment toward the walls.
  • Moat. Even better than a ditch, regardless of whether it was filled with water or not. Moats became more prevalent in the late middle ages. As well as obstructing siege equipment, they made it difficult for the enemy to dig under the castle wall.

Watch Roel Konijnendijk from the University of Oxford's New College analyse battles from movies and television and repeatedly emphasise the importance of ditches.

Bodiam Castle and Moat in Robertsbridge, United Kingdom. It was built to defend the area against a French invasion during the Hundred Years' War.

Bodiam Castle and Moat in Robertsbridge, United Kingdom. It was built to defend the area against a French invasion during the Hundred Years' War.

Medieval Siege Methods

Here are some of the options available to a besieging army:

1. Starve Them Out

The preferred manner of conducting a siege was to simply surround the castle, cut off supply lines, and starve the defenders into surrender.

Of course, if this was that easy, everyone would have done it this way. The reality is most castles were well stocked with enough supplies to hold out for months. Some castles, such as the ones King Edward I established after conquering Wales, were built near oceans so they could be supplied via sea—a massive headache for the commander of the besieging army.

But many commanders were willing to wait a long time if the castle was particularly valuable and the defences too strong to overcome with force. The longest siege in medieval England was the siege of Kenilworth Castle in 1266, which lasted six months.

Scroll to Continue

Read More From Owlcation

2. Demoralise Them

A scene from The Lord of the Rings: Return of the King has the orcs catapulting severed heads over the walls of Minas Tirith. This was actually a popular tactic in the Middle Ages. Terror was more powerful than a trebuchet when wielded effectively against soldiers that were already suffering from starvation and claustrophobia.

Crusaders bombard Nicaea with heads in 1097.

Crusaders bombard Nicaea with heads in 1097.

3. Biological Warfare

What better way to demoralise the enemy than to spread disease and pestilence? Catapulting dead bodies over the walls was not just a terror tactic—it was an early form of biological warfare.

In fact, one of the proposed origins of the Black Death was the Mongol siege of Kaffa in 1346. The Mongols, beset by a mysterious and deadly plague in their camp, began hurling the corpses of those killed by the plague over the walls. The Genoese inside the stronghold were infected and eventually forced to flee by the ocean, carrying the plague back to Europe, where it killed one-third of the population.

The tactics employed by King Henry V are another example. The warrior-king was not so chivalrous as we are led to believe, as during the siege of Rouen in France (1418-19) he ordered his men to throw dead animals into the wells, tainting the water supply.

4. Go Over the Walls

Deploying ladders to try and climb over the walls was basically suicidal, but if taking the castle was pivotal and surrender unlikely, then it would have to be done. Soldiers climbing the ladders would be under constant fire from arrows and rocks.

A better approach was to use siege towers—movable towers that could be constructed on-site and used to approach the walls under cover. Defenders would counter this by attempting to set the towers on fire.

5. Go Under the Walls

Miners would try and dig tunnels under the castle walls. This was a long shot but preferable to scaling the walls under enemy fire.

Prince Louis adopted this approach during the Great Siege of Dover in 1216. His miners burrowed through the chalk beneath the castle walls, causing the eastern tower of the gatehouse to collapse.

Siege towers date back to the ancient world. This image depicts the Siege of Rhodes (305 BC).

Siege towers date back to the ancient world. This image depicts the Siege of Rhodes (305 BC).

Medieval Siege Weapons

Here are some of the weapons used by a besieging army:

1. The Battering Ram

Your most basic siege weapon; easy to construct and easy to operate. Battering rams usually targeted the only weak point in the castle's fortifications—the gate.

The battering ram could be mounted in a frame that protected it from arrow fire, and covered in wet animal hides to (hopefully) prevent it from being set alight.

Engravings on the walls of an Egyptian tomb, dating back to the 11th century BC, show soldiers approaching a fortress with a battering ram, indicating that the weapon was in use at least as far back as the Bronze Age.

2. The Catapult

Another form of artillery that dates back to the ancient world, catapults were deployed in medieval sieges but supplanted by the trebuchet around the 10th century.

3. The Counterweight Trebuchet

The weapon of choice until the advent of gunpowder artillery, the upgraded trebuchet made effective use of gravity through a counterweight that typically weighed ten times as much as the projectile.

They were large, measuring up to 30 meters in height. The largest trebuchet ever built was deployed by King Edward I during his 1304 siege of Stirling Castle and could fling boulders weighing 150 kilograms over a distance of 200 meters.

The trebuchet supplanted the catapult during the Middle Ages.

The trebuchet supplanted the catapult during the Middle Ages.

The Rise of Gunpowder

Gunpowder artillery began to enter the battlefield during the 13th century. The earliest depiction is a 1326 English manuscript showing a cannon on a wooden stand.

Naturally, gunpowder dramatically changed the way sieges were conducted. Not only that, it played a role in bringing about the end of the feudal era by rendering castles redundant.

References

Mark Cartwright. 2018, May 24. Siege Warfare in Medieval Europe (worldhistory.org).

Jack Crawford. 2021, January 22. 7 Powerful Medieval Weapons That Characterized Siege Warfare (thecollector.com).

Matthew J. Broughton. Catapulted Death: Can a Flying Corpse Distribute the Plague? (montana.edu).

Sandra Alvarez. 2014, April 28. Dover Castle and the Great Siege of 1216 (https://deremilitari.org).

Mats Danielsson. 2017, October 11. What Is the Physics Behind a Counterweight Trebuchet? (comsol.com).

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

Related Articles