10 Incredible Medieval Castle Defenses
The power of medieval castle weapons continues to fascinate modern audiences. Whether it's the raw force of a battering ram or the chilling effectiveness of murder holes, these defensive mechanisms showcase human ingenuity and determination to survive.
Castle walls were often lined with machicolations, gaps through which defenders could shoot arrows or drop scalding substances such as boiling water and caustic quicklime onto besiegers. Other defensive measures included barbicans and drawbridges.
1. Gatehouse
The gatehouse was a strong defensive structure that straddled the entrance to the castle proper. It would usually have a passage running the length of it and rooms above.
The defenders could fire arrows from the arrow loops in the battlements above the gatehouse passageway. There was also a'murder hole' (a small opening in a crenellation) through which the defenders could drop missiles or boiling water down on the hapless attackers below.
Some gatehouses also had a portcullis, a heavy metal lattice grill that dropped quickly and locked firmly into holes in the ground. This created another line of defence and trapped whoever managed to breach the gatehouse. Several other defences were often added around the gatehouse including a drawbridge, machicolations and murder holes.
2. Barbican
A barbican was an added layer of defense that protected the main gatehouse entrance. Often shaped like a funnel, the barbican featured one or more secondary gates leading up to the main entrance. This acted as a trap, funneling charging enemies into a narrow passage that would make them easy pickings for archers and crossbowmen.
Castle builders also used attackers' propensity to wield their weapons right-handed against them by requiring they climb towers and the keep's walls on clockwise spiral staircases. This meant their sword-wielding arm was obstructed the entire time they were climbing.
The wards of the City of London known as Cripplegate Within and Without were both incorporated into the Barbican's defenses in the early 14th century. Today, the Barbican is home to a mix of residents including "forgers, professional pick-purses and thieves, conjurors and wizards, beggars and prostitutes." The buildings' appearance and feel are a testament to their history, Ross says.
3. Moat
One of the most crucial castle defenses was a moat. This water-filled trench added a physical and psychological barrier to invaders, discouraging them from even thinking of attacking the castle in the first place. Moats prevented enemy soldiers from simply setting up ladders to climb up the walls, launching a treacherous amphibious assault on boats, or tunnelling beneath them.
They were designed to be a challenge to cross, forcing invaders to wade through filthy water or cross over it using a drawbridge that could be raised during a siege. They also prevented siege weapons, such as battering rams, from getting close to the castle gate.
Although often pictured as large, deep bodies of water, castle moats were generally just dry ditches, although they might have encircled a single building or multiple buildings and even a whole village. Sloped sides and a narrow bottom made it difficult for invaders to approach the castle wall directly.
4. Drawbridge
A drawbridge was a movable bridge that could be pulled in over the castle gatehouse to block access. This was a crucial part of a castle’s defences in that it prevented invaders from advancing over the moat and into the castle itself, or tunneling under it to reach the gates.
Located at the entrance of the castle, they were also commonly accompanied by portcullis and moat for added security. During peacetime, these movable bridges functioned as controlled entry points for residents, visitors and traders, regulating economic activity and asserting the authority of the castle’s lord.
They were often designed to be lowered by hand, but later medieval castle drawbridges incorporated systems of ropes and chains or even pulleys so that they could be raised and lowered much faster. This was to ensure that the castle was ready for battle at all times, preventing the enemy from gaining ground in case of a surprise attack.
5. Machicolations
In medieval times, castles weren’t just fancy symbols of royal grandeur – they also played an important role in the battle for control of kingdoms and dynasties. In a time when wars, invasions and local skirmishes were a regular occurrence, the development of castle defence weapons became a top priority. Machicolations were one of these defence weapons.
A machicolation (french: machicoulis) is a floor opening in a projecting parapet wall, similar to a balcony, through which stones or other materials could be dropped on attackers below. Often found on a castle's walls, they could be used for dropping stones, boiling water or other objects, and even unpleasant substances such as sand, quicklime, pitch and boiling cooking oil.
They were built into castle walls and were best located above the most critical points, such as doors, gateways or towers. Because of their location, they were highly visible and acted as a strong visual deterrent to any potential attackers. Also known as ‘murder holes’, machicolations were introduced with the Norman and Plantagenet castles during the medieval period 1066 - 1485.
6. Murder Holes
During the High Middle Ages, castles evolved from wooden palisades and ditches into massive stone fortresses with multi-layered defensive strategies. Murder holes, for example, were openings in a castle wall through which defenders could physically attack besiegers. They were a deadly and inventive addition to medieval warfare, enabling defenders to hurl rocks, arrows, boulders, boiling water, hot sand, caustic quicklime and even searing hot oil at their enemy troops below.
These narrow openings in castle walls (also known as arrow loops) gave defending archers a fantastic vantage point over their attackers and allowed them to fire arrows at them while remaining safe behind the castle's walls. They were also used to shoot flaming arrows at the siege towers and cannons of besiegers, burning them down.
Murder holes are a sub-type of another medieval castle defense, the machicolations. Unlike murder holes, which were built into existing castle walls, machicolations were built into the corbels, or the parts that stick out above a castle wall.
7. Defensive Towers
Defensive towers were used to scout for enemy troops approaching the walls, giving defenders a chance to shoot them with arrows or other projectiles. They could also be fitted with murder holes, through which defenders would drop or pour things like boiling water on any hapless attackers below.
In the medieval period, towers developed into a variety of shapes, including square and circular. The rounded sides of these towers made it difficult for attackers to get close enough to use siege engines. They also were less susceptible to mining, when sappers dug underneath the castle walls in an attempt to breach them.
Some of the tallest towers were positioned at the gates to the castle’s keep. They were often fitted with spiral staircases, which forced attackers to fight their way up them while exposing themselves to the defenders below. This may be the reason why the word donjon has become synonymous with dungeons.
8. Tower Gates
The barbican and gatehouse made it hard for attackers to approach the castle’s main entrance, but even if they did make it that far they would be exposed to a withering hail of arrows. The gates themselves were another formidable barrier, with many featuring a portcullis that could be lowered to block the passageway or raise it to allow access.
These gates were also often constructed with arrow slits and murder holes (known as machicolations). The latter were holes in the projecting battlements above the gate through which missiles or burning liquid could be dropped onto attacking soldiers massed below.
These defensive features were just one element of a complex series of barriers that made it almost impossible for an enemy to breach a castle, even with the help of siege weapons like catapults and black plague. It would take a determined and fierce enemy to overcome multiple layers of defences such as these, and they would likely be wiped out in the process.
9. Postern Gates
While castles in the Middle Ages may look like extravagant displays of grandeur, they were built to serve as ultimate deterrents against invaders. In addition to their imposing walls, medieval castles were equipped with a variety of defense weapons that were meticulously tailored to specific threats. Arrow slits, for example, were narrow vertical openings in wall surfaces that allowed defenders to shoot arrows at enemies while remaining almost entirely shielded from attack. Murder holes, on the other hand, allowed defenders to drop boiling oil, heavy rocks, and other deadly materials onto unsuspecting invaders, causing significant casualties without direct combat.
Postern gates, also known as sally ports, were small, hidden gateways in a castle’s curtain wall that were big enough for one person to pass through at a time. This feature was particularly useful for defending against incoming archers as they could quickly and inconspicuously exit the castle to fire back at their attackers.
