Medieval Siege Warfare


This post and the flash fiction post that accompanies it (which can be found here) are the first posts I’ve done for almost two weeks. I was away from home for eight days, and since being back we’ve been invaded by family and had several outings. So I must apologise to all those people whose posts I’ve missed. I hope to catch up on at least some of them.

So, this is a brief summary of some of the methods of besieging a castle.

By the 12th and 13th centuries, castles had evolved into powerful fortresses, able to withstand great assaults. Once the portcullis was down, the gates closed and drawbridge raised, they were very difficult to attack:

Bodiam Castle throughthe trees (Sussex UK) Author Pilgrimsoldier. Wikimedia Commons
Bodiam Castle throughthe trees (Sussex UK) Author Pilgrimsoldier. Wikimedia Commons

Medieval soldiers used a variety of methods to breach the castle defences and sieges were common. Siege tactics became very complex and did not just involve attackers rushing at the castle – which would risk the loss of too many men.

To begin with, leaders would search the realm in order to employ the best archers, carpenters, blacksmiths, sappers and engineers … and once they were all in place at the castle, the procedure followed a general pattern:

First, the castle would be surrounded, thus cutting off any means of escape and all supplies to the inhabitants. At the same time, besiegers would ensure that their own encampment was fortified, sometimes even constructing an earthen embankment around it and organising a constant night watch. Then they would simply wait for the lord of the castle to surrender – which could take many months. If the lord still refused to surrender, assault on the castle would commence.

By this time, attackers would have located the castles weakest points, such as the weakest doorways and lowest curtain walls – preferably with no outer river or moat, which entailed using barges to cross them.

The River Avon acts as a natural moat along the curtain wall of Warwick Castle
The River Avon acts as a natural moat along the curtain wall at the eastern side of Warwick Castle.

It stands to reason that gateways are likely to be the weakest points, and they would be attacked first. To do this, a battering ram came in useful (of which there were many sizes and designs):

Medieval battering ram at Chateau des Baux, France. Photo: ChrisO. Commons
Medieval battering ram at Chateau des Baux, France. Photo: ChrisO. Commons

Many castle gateways, particularly the main ones, were heavily fortified by a series of structures and mechanisms (like drawbridges, portcullises and thick wooden doors, as well as ‘murder holes’ above the inner passageway, should attackers get that far). A fortified outpost or gateway, like this one at Warwick, was called a barbican:


At the same time as the gateways were being attacked, ladders would be carried up to scale the walls, often to be met by defenders who simply pushed the ladders away, or greeted rising besiegers with boiling oil. For scaling the walls, lofty siege towers (or belfries) were wheeled up. At the top of these was a drawbridge which would be lowered to allow men to stream out and attack defending guards. Sometimes, belfries were used from a distance to fire arrows down into the castle.

Medieval English siege tower. Author: Grose-Francis. Public Domain
Medieval English siege tower. Author: Grose-Francis. Public Domain

Other machines (effectively different versions of catapults) were designed to breach the castle walls and towers by hurling large rocks and missiles at them. Dead animals were also hurled over the walls in the hope of spreading disease amongst the inhabitants.

Trebuchets were built in all shapes and sizes, some with wheels so they could be moved around the castle. They were massive, gravity-powered catapults, consisting of a lever and sling and capable of hurling rocks of up to 200lbs for 300 yards. They could also be disassembled in order to transport them from place to place. This is one we saw at Warwick Castle:


The mangonel also hurled boulders, and had a throwing arm like the trebuchet, but it was less accurate than the trebuchet, with a shorter throwing range, and aimed directly at the castle walls rather than over the top of them.It worked by torsion:

English mangonel. Author: Rpanjwani. Commons
English mangonel. Author: Rpanjwani. Commons
Medieval Mangonel. From "Dictionary of French Architecture fron 11th-16th Century" by Eugene Viollet in 1856. Public Domain,
Medieval Mangonel. From “Dictionary of French Architecture fron 11th-16th Century” by Eugene Viollet in 1856. Public
Mangonel shot used in the siege of Bedford Castle in 1284. Author Simon Speed. Public Domain
Mangonel shot used in the siege of Bedford Castle in 1224. Author Simon Speed. Public Domain.

A ballista was built like a huge crossbow and designed to shoot bolts (huge,metal-covered arrows) into the castle. It was manoeuvrable and played an important part in sieges for over a thousand years, originating in ancient Greece. This weapon utilized two torsion springs and two throwing arms to launch its load along a central track.

Some ballistas also hurled rocks, like this one we saw at Warwick Castle:


While all this was going on at the top of the castle, miners/sappers would be busy tunnelling up to the castle and tower walls in order to collapse them. To do this they would remove the foundation stones and replace them with wooden props. A fire would then be lit and the miners got out quick! Once the props burnt through, there would be nothing to hold up the wall, so it simply collapsed. The corners of square castles were the weakest parts and miners would often aim for those. Inside the castle, guards would place pots of water near the towers and walls. When the water rippled, they would know that enemy miners were at work.

Needless to say, a great variety of hand weapons were used during attacks, amongst others a variety of swords, knives, axes, spears, clubs, maces, flails, halberds, crossbows and longbows. And all soldiers would be heavily weighted down with necessary armour. It’s always mind-boggling to think of the enormous weight medieval soldiers had to carry whilst fighting for their lives.

Naturally, defenders had many techniques for countering attacks on their castles, a few of which I’ve mentioned above, and not every siege was successful …


Castles of North Wales: Conwy
Conwy Castle and car park from the Town walls, viewed from the south west. Source: Author: David Dixon. Creative Commons

The castles of King Edward I (1272-1307) in North Wales are amongst the finest medieval buildings in Britain. They were all built from scratch, often concurrently, in the unsettled aftermath of war. During my trip to Wales last week I’ve been to see just three of these castles. The simple map below shows their locations. Beaumaris is on the Island of Anglesey, across the Menai Straits:

North Wales Castles
Map showing three North Wales castles. Base map from Image:uk map,svg. Author: Paul at wts.wikivoyage. Wikimedia Commons.

Conwy Castle was built on a new site in the spring of 1283 as part of a ring of fortresses encircling the Welsh heartland of Snowdonia in Gwynedd. It followed Edward’s victory of his second campaign to subdue the Prince of Wales, Llwelyn ap Gruffudd. There had been conflicts in this region for many years between the Plantagenet kings of England (John 1199-1210 and Henry III 1216-72) and the princes of Gwynedd – notably Llwelyn ab Iorwerth, also known as Llwelyn the Great. (ab/ap are derived from the Welsh word mab, which means ‘son of”.)

Neither John nor Henry challenged the Prince of Gwynedd successfully, and on Edward’s succession in 1272 the prince’s refusal to do homage to the English king resulted in the war of 1276 -77. Edward’s victory was rapid – if, ultimately, inconclusive – but his second war (1282-3) proved more decisive.

The castle was built as part of a wider project to create the walled town of Conwy in order to control an important crossing point over the River Conwy. The whole project cost £15,000 – equivalent to £45 million today. The castle was intended as a centre for the administration for the area, but Caernarfon became the shire town and assumed that role. Edward only stayed at Conwy once.

Here are a couple of pictures of a model on display inside the castle. They show the castle and part of the walled town as they would have originally looked. Note the direct access to the River Conwy:140


The plan below shows the castle from the same (south) side as the last picture. The plan is roughly rectangular, with four towers spaced regularly along each side. The bulging outer (south) wall can be seen clearly on each, probably the result of the builders following the contours of the rocky outcrop. The great hall and chapel in the outer ward curves in line with this wall. The four towers closest to the river have small, round turrets overlooking the inner ward, where the royal apartments were located.

Conwy Castle plan. Source: Cadw. Open Government Licence. Wikimedia Commons.

The castle is noted for its high towers and curtain walls, and its excellent state of preservation:

Inside the imposing outer shell the castle contains the most intact set of residential buildings left by medieval English monarchs in Wales or England. The outer ward – 2/3 of the main castle area – contains the great hall and chapel, as well as the chambers, stables and kitchen that served the garrison.

This is the outer ward. The two photos, bottom left are of the great hall and chapel. The chapel is at the far end, where the arched window can be seen.

The inner ward has the private chambers (top left photo below) and the royal chapel. A water gate, leading to the east barbican (gateway) provided private access for the king and queen. Here are some photos taken mostly from around the battlements, with an odd one or two inside the towers. Most look down into the inner and outer wards, or show views out across the River Conwy:

The suspension bridge ascross the R. Conwy (middle bottom) was designed by Thomas Telford and completed in 1826.

I’ve missed out so much detail about Conwy Castle, as well as many of the photos we took, otherwise this post would become a marathon.