© 2001-2016 by Lise Hull
A curtain wall, or enclosing wall, of a castle bounded or enclosed the castle. Most often it was attached to the towers and gatehouse. There are examples of walls dividing or splitting a bailey into two wards, and this is called a cross-curtain. Some curtain walls would be built around the bailey of a motte castle.

The early curtain walls were made of heavy timbers and are most often associated with motte and bailey castles. These walls were called Palisades. The timbers would be locked together with horizontal beams and braced or propped in the back. Sometimes, these were so very well constructed that they were not replaced with stone curtains for as long as a century after the castle was built.

Curtain walls made of timbers were prone to decay in a very short time. They were also susceptible to fire, by attackers or by accident. Stone, much sturdier than wood, gradually replaced most of the timber curtain walls. One of the earliest stone curtain walls was at Richmond Castle, built in 1075.

The average height of a curtain wall was about 30 feet. There are a few exceptions, such as at Framlingham Castle. The stone curtain wall there was 44 feet high, while Knareborough Castle's was 40 feet high. The width varied, but most were very thick. They ranged from 7 feet thick at Conisbrough Castle to 20 feet thick at Chepstow Castle. Dover Castle walls were 20 feet thick, while Duffield Castle walls were 18 feet thick. Fortified manors had thinner curtain walls, ranging from 3 feet to 7 feet thick.

As siege engines improved, the curtain walls were built higher. This made the lower part, or the base of the curtain wall, vulnerable to breaching and undermining. This problem was solved by introducing hoarding, allures, and angle towers. Curtain walls were almost always battlemented and had a parapet near the top and inside of the wall.

Curtain walls were a very important part of the castle defense. Once the wall was breached, the castle would surely fall to attackers.

Here are some of the earliest castle curtain walls built:
Brough (1095), Ludlow (1086), Richmond (1075), Rochester (1087).

Stone Wall Construction
The best way to start the construction of a castle wall was to dig down to the bedrock, then quarry it flat for the foundations. If solid bedrock was not available then laborers had little choice but to dig trenches wider than the width of the wall and fill them with rubble. The rubble would then be compacted. Another method would be to try and use an existing foundation to build the new wall.

The walls could be made of rubble, framed with wood until the mortar had dried. The most common composition was a rubble core with ashlar facing. The ashlar would be fitted in horizontal rows called courses, which could also be supplemented by slate to keep everything nice and level.

Once the walls got too high to reach then workers would erect scaffolding to assist in construction. They would place timber posts into holes or containers and then lash them together with rope. Then, the ends of the timber would be inserted into putlog holes built into the wall. After the scaffolding was built, stone and mortar and other materials would be lifted by pulleys, hoists, or by carrying them up a ramp.

Once the wall was at its full height, it was levelled off and ready to receive the allure and parapet. Laborers would then build a stone staircase parallel to the wall to provide access to battlements. They would coat the finished wall with plaster and whitewash to protect the stone and mortar. Names like the White Tower (at the Tower of London) or White Castle derive from the presence of this plaster.

Imagine, if you will, a castle such as Beaumaris in Wales. The curtain wall was 35 feet high, 10 feet thick and 1,200 feet long. Think of how much stone was used, time involved, and how many men it took to build it. No wonder castles took decades to complete, if they were completed at all!