top of page

Medieval Castles: Defense

Wall Walks and Allures

An allure was a feature of medieval fortifications that served both a functional and aesthetic purpose. It was essentially a walkway that ran along the top of a curtain wall, providing those on it with a commanding vantage point from which to survey the surrounding landscape. To access the allure, one would use a wooden or stone stair that ran parallel to the wall, or sometimes a mural tower. The allure was not only a practical defense against attackers, but was also a symbol of the wealth and power of the fortification's owner. In addition, it was often adorned with decorative elements, such as crenellations, corbels, or machicolations, that further enhanced its visual appeal. Overall, the allure was a crucial element of medieval fortifications, combining both form and function in a way that made it an enduring feature of castle architecture.

Wall-walks, which were a common feature of medieval fortifications, were often paved with stone slabs. These slabs were carefully selected for their durability and strength, ensuring that they could withstand the weight of soldiers and the wear and tear of daily use. In addition to providing a sturdy surface for walking, the stone slabs also served as a decorative element, adding to the visual appeal of the fortification. They were often cut into intricate patterns and designs, showcasing the skill and craftsmanship of the stonemasons who created them. Overall, the stone slabs used to pave wall-walks were an essential component of medieval fortifications, both in terms of their practical function and their aesthetic value.

During the later 13th century, architects created an overhanging allure, a unique architectural feature that was further developed into flying parapets and machicolations. These additions not only served as a way to enhance the aesthetic appeal of the architecture but also provided a practical function by offering additional defense against invaders. The overhanging allure helped to prevent enemies from approaching the castle walls, while the flying parapets and machicolations allowed the defenders to drop hot liquids or heavy objects onto any invaders who managed to get too close. These innovations were a testament to the ingenuity and creativity of medieval architects, who were constantly seeking new ways to improve the security and design of their fortifications.

Arrow Loops

Arrow loops, also known as arrow slits or bow loops, were a common feature in medieval fortifications. These narrow openings were designed to provide defenders with cover while allowing them to fire their arrows at attackers. They were often strategically placed in castle walls and towers, and were particularly effective against archers. Some arrow loops were also designed to be adjustable, allowing defenders to change the angle of their shots depending on the location of the attackers. Overall, arrow loops played a crucial role in the defense of medieval castles and fortresses.

Before 1190, it was rare to find windows in buildings. The few that existed were usually just a simple vertical slot that was less than two inches wide at the outside. These slots were not designed for decorative purposes but rather for functional reasons such as ventilation and light. They were not very long either, averaging between 3 to 12 feet in length. However, as architectural styles evolved, windows became more elaborate and were designed to serve both functional and aesthetic purposes. Today, windows come in various shapes and sizes and are an integral part of any building's design.


In the late 12th century, there were significant developments in castle architecture. One such development was the introduction of the splayed foot, which was designed to create a wider base in the slot, allowing soldiers to have a better range of aim over a larger area outside the castle. This was particularly important for defending against attackers. Another development at this time was the introduction of horizontal slits, which provided soldiers with a better line of sight to the outside of the castle. The combination of these two innovations made castles much more formidable and difficult to penetrate. As a result, they remained a key part of the military landscape for centuries to come.

During the 13th century, the design of arrow loops continued to evolve and improve. One notable change was the rounding of the ends of the slits, which came to be known as oillets. This change not only improved the functionality of the arrow loops, but also added a decorative element to the design.

Additionally, as fortifications became more advanced, more than one cross-arm came into use, allowing for greater flexibility in the direction of fire. Some arrow loops during this time period were especially massive, with lengths of up to 17 feet and triple cross-arms. These impressive structures served as both a testament to the ingenuity of medieval engineers and a powerful deterrent to potential attackers.


The barbican was an essential part of a castle's defensive system, serving as an exterior fortification that protected the entrance from enemy attacks. Typically, the barbican was constructed as an enclosed space that was heavily fortified, featuring high walls, towers, and a drawbridge that could be raised in case of danger. In addition to being a military stronghold, the barbican also served other functions, such as a checkpoint for travelers and a storage area for supplies. Overall, the barbican played a crucial role in the defense of castles during medieval times, providing a strong line of protection against potential threats.

The military tactic of confining an approaching enemy to a narrow front, as described in the document, was a strategy commonly used in medieval warfare. While it was effective in limiting the enemy's advancement, it also had its drawbacks. By leaving the attackers in the open, it exposed them to the castle defenders, who could then launch a barrage of projectiles at them. Moreover, the tactic required the defenders to have a strong and well-fortified position, as any breach in the castle walls could result in the attackers gaining access and turning the tables on the defenders. Thus, while the tactic had its merits, it was not foolproof and required a careful balance of offense and defense to be successful.

During medieval times, barbicans played a crucial role in the defense of castles and fortresses. These structures were built to protect the gates of the castle, and their intricate design made it difficult for attackers to penetrate the castle walls. The barbican was also used as a place to store weapons and supplies, making it an essential part of the castle's defense system. Additionally, during a siege, the barbican served as a first line of defense, allowing the defenders to launch surprise attacks on the enemy. The attackers, on the other hand, found themselves in a hopeless maze of twists and turns, often confused and unable to find their way out. All in all, the barbican was a crucial component of medieval castle architecture and played a significant role in the defense of these structures.

The most common type of gatehouse design during the medieval period was a walled passage that projected from the front of the main structure. This design served to provide additional protection to the gatehouse by creating a defensive barrier that would impede enemy forces from gaining entry. It also offered a tactical advantage in that the defenders could use the cover of the passage to launch attacks on the enemy. Additionally, the projecting passage was often designed with a portcullis or drawbridge at the entrance, which provided an additional layer of security against attackers. Overall, this design was a crucial element of medieval castle architecture and played a key role in the defense of castles during times of war and conflict.

Bartizans and Bastions

In the field of architecture, particularly in medieval times, bartizans were essential elements of a tower's defensive design. A bartizan was a small, fortified turret or lookout that projected out at an angle from the main structure of a tower or wall and which was supported by corbels. These structures were used by guards as a lookout point, to help them keep a watchful eye on the surroundings and to protect the tower or wall from potential intruders. Bartizans were often built with arrow slits or gun holes to allow guards to fire upon any would-be attackers. They were a vital feature of medieval architecture, and their design and purpose can still be seen in many castles and fortresses around the world today.

The bartizan, which was a type of overhanging turret or small tower, was almost always located at one of the highest points of the castle. It was often used as a lookout point for soldiers to survey the surrounding area and detect any approaching enemies. In addition to its practical function, the bartizan also served a decorative purpose and was often adorned with intricate carvings or designs. The bartizan was a prominent feature of many castles, and its location and design varied depending on the architectural style of the castle and the preferences of its builders. Despite its small size, the bartizan played an important role in the defense and aesthetics of medieval castles.

The bastion, a crucial element in fortification design, served a multifaceted purpose. It was a prominent projection, jutting out from the main structure, which served to cover dead ground, or areas adjacent to the fortification that were not visible from the main structure and thus vulnerable to enemy attack. In addition, it served to flank curtains, or the connecting walls between bastions, providing additional defensive coverage against enemy assaults. Lastly, the bastion was designed to provide crossfire, or a situation in which an enemy attempting to attack from one side would be caught in a deadly crossfire from the bastion, making it an even more formidable defensive structure.

Batter, Battlements, and Embrasures

A batter, plinth or spur is the angled footing of a wall or tower. These architectural features have been used throughout history to provide a stable foundation for tall structures. In ancient times, engineers and builders would use batters to counteract the effects of undermining, which was a common tactic used by enemy armies to breach the walls of a fortress. The incline of the batter would help to distribute the weight of the structure more evenly, making it more resistant to collapse. Additionally, spurs were often added to the sides of a plinth to cause dropped missiles to ricochet horizontally, further preventing damage to the structure. Overall, the use of batters, plinths, and spurs has played a crucial role in the construction of stable and secure buildings and fortifications throughout history.

The battlements, also known as crenellations, were an essential part of the castle's architecture. They served several purposes, including providing a walkway at the summit of the wall, a platform for soldiers to fight from, and, most importantly, a defense mechanism against escalade. When an enemy attempted to scale the walls of the castle, the soldiers stationed on the battlements could use a variety of weapons to repel the invaders, including arrows, boiling oil, and rocks. This made it extremely difficult for attackers to breach the castle's defenses, ensuring the safety of those inside. Additionally, the battlements were often decorated with intricate designs, adding to the castle's aesthetic appeal. Overall, the battlements were a crucial feature of medieval castle architecture, both from a defensive and aesthetic perspective.


An embrasure, also known as a crenel, is a commonly used architectural feature in military fortifications. These splayed openings in a wall are used to provide a firing point, allowing soldiers to defend the fortification from enemy attacks more effectively. Embrasures can be seen in various forms, from simple slits in the wall to more complex openings with additional protections, such as angled walls or steel plates. The use of embrasures dates back to ancient times, with early examples being found in fortifications built by the ancient Greeks and Romans. Today, embrasures continue to be used in modern fortifications, such as those found in military bases around the world.

The architectural structures in question, commonly referred to as embrasures, were typically designed to be anywhere from 2 to 3 feet in width. These embrasures were then separated by intervening merlons that rose to heights of anywhere from 3 to 7 feet and were approximately 5 feet wide. This particular design was of great importance, as it allowed for the defenders to have a clear view of the surrounding area while also offering ample protection from incoming attacks.

During the medieval period, battlements were not only used as a defensive feature on castles, but also on unfortified structures such as manor houses or churches. This was done to create a sense of grandeur and power, as well as to evoke the image of a castle, which was seen as a symbol of strength and security. In some cases, battlements were even added to buildings purely for decorative purposes, without any practical function, as a way to display the wealth and status of the building's owner. Thus, the use of battlements on non-military structures became a common architectural feature during this time period, serving both a practical and symbolic purpose.

Berm, Braie, and Cross Wall

In medieval times, castles were a crucial part of warfare and defense. The area between the castle curtain wall and the ditch or moat was known as the berm. It was a level space that provided an open area for defenders to maneuver and engage the enemy. The braie, on the other hand, was an exterior defense of small height that hindered an attacker's approach. Made most commonly of earth, it was a simple but effective means of defense. Meanwhile, cross walls were often used as interior or exterior dividing walls. Some of these walls went across the bailey, while others divided the keep or other structures. These walls provided additional defense and helped to compartmentalize the castle, making it more difficult for attackers to penetrate the castle's defenses. Overall, castles were complex structures that required careful planning and design to ensure that they were effective at protecting those inside from enemy attacks.

Curtain Wall and Arrow Slits

The curtain wall was an important defensive feature of castles in the medieval period. It surrounded the bailey or castle buildings and was often connected to flanking towers. The wall could vary in thickness from 6 to 20 feet, depending on the size and importance of the castle.

One interesting feature of some curtain walls were arrow slits. These were narrow openings, often with a triangular or rectangular shape, which allowed the castle defenders to shoot at attackers while remaining safely behind the wall. The arrow slits were strategically placed in the curtain wall to provide maximum protection and visibility.

In addition to providing protection from attack, the curtain wall also served a symbolic function. It marked the boundary between the castle and the outside world, and demonstrated the power and wealth of the castle's owner.

Overall, the curtain wall and arrow slits were important components of medieval castle design, providing both defense and symbolism to these impressive structures.

Drawbridge and Gatehouse

In the Middle Ages, castles were designed with many features to protect the inhabitants from attackers. One such feature was the drawbridge, a moveable wooden bridge spanning the castle ditch or moat. It could be removed or raised to prevent easy entry into the castle. The drawbridge was an important aspect of castle defense because it made it difficult for the attackers to penetrate the castle walls.

Another important feature of castle defense was the gatehouse, which was the entrance to the castle. The gatehouse contained at least one portcullis that could be raised or lowered, making it difficult for attackers to enter. The portcullis was a heavy gate made of metal or wood and fitted with sharp spikes. It could be dropped quickly to trap attackers in the gateway.

Vaulted ceilings in the gatehouse could contain murder holes and arrow slits in the side walls. Murder holes were openings in the ceiling through which defenders could drop rocks, boiling water, or other objects on attackers. Arrow slits were narrow openings that allowed defenders to shoot arrows at attackers while remaining safely protected behind the walls.

Hoarding, or brattice, was another feature developed to cover dead ground, or blind spots at the base, or foot, of the curtain wall. It was a wooden platform built on the top of the wall which enabled defenders to shoot at attackers from above while protecting themselves. The hoarding was an important feature because it allowed defenders to see and shoot at attackers below, who were otherwise protected by the wall.

Keep, Machicolations, and Merlons

During a siege, the keep served as a self-sufficient, last resort, place of refuge. It was designed to withstand attacks and offer protection to the people inside. Additionally, it often served as a symbol of power for the people who owned it.

The machicolations, which were openings in the floor of a projecting parapet or platform along the wall or above an archway, had a strategic purpose in battles. They allowed the defenders to drop or shoot missiles vertically on attackers below, giving them an advantage over the enemy forces.

Merlons, on the other hand, were solid parts of a crenellated parapet that protected the defenders from enemy fire. They were sometimes pierced with arrow slits, which allowed the defenders to shoot arrows at the attackers while remaining safe behind the merlons. This design was crucial in battles and sieges, as it allowed the defenders to hold their ground and defend their position.


Moats, Murder Holes, and Castle Defense

In medieval times, castles were built to protect their occupants from attackers. One of the most important defenses was the moat. A moat was typically filled with water from a nearby source, such as a spring, lake, stream, or river. It surrounded the castle and made it difficult for attackers to approach the walls. However, attackers were known to use portable bridges or barges to span the moat and besiege the castle.

To further protect the castle, defenders used murder holes. These were openings in the castle floor through which the defenders could drop missiles or liquids upon attackers who had breached the castle walls. Another important element of castle defense was the parapet. This was an embattled wall that shielded the castle defenders on the wall-walk. The wall-walk was a platform on top of the castle walls that allowed defenders to move quickly from one part of the castle to another.

In addition to the moat, murder holes, and parapet, other castle defenses included drawbridges, portcullises, and battlements. Each of these elements played a crucial role in protecting the castle and its occupants from attackers.


Towers were a crucial element in castle architecture, serving multiple purposes. They provided access to the wall walks, lookout points and sleeping quarters for the castle garrison. Apart from the practical uses, towers were also significant defensive features, helping to protect the castle from outside threats.

Towers came in different shapes and sizes, with the most common being square, D-shaped, or round. The choice of shape depended on the intended use of the tower, with some towers designed for more practical uses such as storage or accommodation, while others were specifically constructed for military purposes.

Interestingly, the construction of towers was a challenging task, requiring skilled labor and extensive resources. The process involved careful planning and execution, with materials such as stone and timber being used to create the structure. Once completed, the tower was a testament to the skill and craftsmanship of the builders, and an impressive sight to behold.

In summary, towers were a vital aspect of castle architecture, serving both practical and defensive purposes. Different shapes and sizes were used depending on their intended use, and their construction required skilled labor and extensive resources.


Annotated Bibliography

  1. Toy, S. (1985). The Castle. London: B. T. Batsford.

This book provides an in-depth look at the history and architecture of castles, with a focus on the medieval period. It covers the development of castle design, the various types of castles, and the role of castles in medieval society. The book also includes numerous illustrations and photographs, making it an excellent resource for anyone interested in the topic.

  1. Johnson, M. (2010). Castles: Their Construction and History. New York: Dover Publications.

This book provides a comprehensive overview of castle construction and architecture, from the earliest fortifications to the grand castles of the medieval period. It covers the various types of castles and fortifications, as well as their role in medieval society. The book includes detailed illustrations and photographs, making it an excellent resource for anyone interested in the subject.

  1. Kaufmann, J. E., & Kaufmann, H. W. (2004). The Medieval Fortress: Castles, Forts, and Walled Cities of the Middle Ages. Cambridge, MA: Da Capo Press.

This book provides a detailed look at the design and construction of medieval fortifications, including castles, forts, and walled cities. It covers the various types of fortifications, as well as their role in medieval society. The book includes numerous illustrations and photographs, making it an excellent resource for anyone interested in the subject.

  1. Creighton, O. (2002). Castles and Landscapes: Power, Community and Fortification in Medieval England. London: Equinox Publishing.

This book provides a comprehensive look at the relationship between castles and the landscape in medieval England. It covers the various types of castles, as well as their role in shaping the landscape and influencing the development of local communities. The book includes numerous illustrations and photographs, as well as detailed maps, making it an excellent resource for anyone interested in the subject.

  1. Friar, S. (2003). The Castle: History and Description. London: Conway.

This book provides a comprehensive overview of castle history and architecture, from the earliest fortifications to the grand castles of the medieval period. It covers the various types of castles, as well as their role in shaping medieval society. The book includes numerous illustrations and photographs, making it an excellent resource for anyone interested in the subject.

Recent Posts

See All


Rated 0 out of 5 stars.
No ratings yet

Add a rating
bottom of page