Whether you’re into Disney movies, Middle Earth, or Game of Thrones, we all seem enchanted with medieval castles. However, while we imagine them as a fairy tale palace, they were medieval house fortresses for European nobility. Though you’ll also find castles in Asia, Africa, and the Middle East. Castles originated in the 9th and 10th centuries as the fall of the Carolingian Empire resulted in individual lords and nobles dividing the territory. To control the area surrounding them, these guys built castles as both offensive and defensive structures. Castles provided a base to launch raids and protect from enemies. Though castle studies often emphasize their military origins and see castles as “a fortified private residence,” they also served as centers of administration and power. Urban castles were used to control the local populace and important travel routes. Rural features were often near features integral to life and community like mills, fertile land, or a water source. Though most medieval castles in Europe today are made from stone, many were made from wood, especially in the early Middle Ages. Due to lacking arrow slits and towers, early castles often exploited natural defenses and relied on a central keep. But as a scientific approach to castle defense emerged, leading to tower proliferation and emphasizing flanking fire. Taking inspiration from Roman forts and technology from the Crusades, you’ll find some concentric castles. Nevertheless, since all things much come to an end, castles began to decline began to decline with the introduction of gunpowder which made them uncomfortable and undesirable places to live. Though these structures still captured the imagination enough to make aristocrats want to build castle like houses, but without the key defenses.

The first part of this series will focus on the outermost components like the walls and what’s outside them. As the first line of defense, such structures would have to make invasions and sieges incredibly difficult for the enemy. Before a castle was built, you’d often construct an artificial hill called a motte and a ditch filled with water called a moat. A castle’s walls had to be high enough to make scaling with ladders impossible. And they had to be thick enough to withstand bombardment from siege engines. Though sizes vary, a typical castle wall could be 10 feet thick and 39 feet tall. They’d also have stone skirts around their bases to prevent infiltration as well. Walkways on top of curtain walls allowed defenders to rain arrows on the enemies below with battlements giving them further protection.

Outside the Walls

Berm- a flat piece of land between the curtain wall and the moat protecting it. Intended to reduce soil erosion to keep the wall from collapsing. Also kept debris from the wall from falling into and filling the moat.

Bivalate- a pair of defensive ditches or earth embankments surrounding a mound or medieval castle.

Caponier- a covered passage within a ditch.

Caponiere- a covered passage across a ditch to an outer fortification structure like a ravelin.

Counterscarp- outer slope of a ditch.

Couvre Face- a low rampart in a ditch protecting the ravelin’s face.

Covered Way- a protected communication wall all around the ditch’s outer edge, covered by earthworks from enemy fire.

Crownwork- a freestanding fortification built in front of the main defenses.

Cunette- a trench at a ditch’s bottom.

Ditch or Fosse- a common defense dug around the castle’s outside walls and the resulting earth to create banks. Most were dry but some were filled with water to create moats. The steeper the ditch sides, the better since it made it more difficult for attackers to climb. Though ditches weren’t filled with water, rainfall would’ve created a muddy obstacle to cross. The castle’s toilets also emptied into it, giving attackers another disgusting problem.

Earthwork- fortification made of earth mounds, banks, and ditches.

Glacis- a bank sloping down from a castle which acts as a defense against invaders. Consists of broad, sloping, naked rock or earth on which the attackers are completely exposed.

Hornwork- an independent earthwork located in front but not connected to the curtain wall within its bastions’ range (so it can be defended by them). Had long parallel sides with a back shaped like a crescent moon facing the castle’s curtain wall. But was built so low so it couldn’t shelter attacking forces if overrun. Forced attackers to start their siege further away from the castle and gave defenders a better chance to destroy siege lines before they could reach the structure.

Moat- a deep, wide ditch surrounding a castle’s outer walls. Often filled with water from diverted rivers, lakes, or springs with a special dam. Mostly had an inlet and outlet of water rather than being a self-contained donut (unless the castle was built on an island in the middle of a lake). It was often around 3-30 feet deep and at least 12 feet wide. It was sometimes within the outer wall or between the outer wall and the inner wall. Its primary purpose wasn’t to stop attackers but siege weapons, siege towers, battering rams, and most importantly, tunnelers. Since tunneling a castle was an effective means of collapsing the walls or infiltrating it. A moat would cause any tunnel to collapse through flooding. Also, gave valuable time for castle defenders to form strategies for subsequent defense. Sewage was often tipped into the moat so it would smell pretty unpleasant.

Motte- a natural or artificial hill with a flat top upon which a castle was built. Was constructed from dirt and rocks to a height between 10 and 100 feet.
Neck Ditch- a ditch cutting across a neck of land to hinder an enemy’s advance.
Place of Arms- an enlarged area in a covered way where troops could assemble.
Ravelin or Demilune- a triangular earthwork located in front (but not connected to) the curtain wall, within range of the curtain wall’s bastions. The back was shaped like a crescent moon and faced the curtain wall. But built low so it couldn’t shelter attacking forces if the ravelin was overrun. The front sides also had a defensive wall of their own. Allowed defenders to fire upon attacking troops before they could reach the curtain and a better chance to destroy siege lines before they could reach the castle. Forced attackers to start their siege further away from the castle.

Revetment- a retaining wall to prevent erosion.

Scarp- a slope on a ditch’s inner side.

Tilting Yard- yard or field where jousting tournaments and combats took place. Usually situated just outside the castle’s confines.

Watergate- a gate allowing a coastal castle to be resupplied by sea, especially during a siege.

The Walls

Allure or Wall Walk- walkway at the top inside of the curtain wall, which allowed guards to look for enemies. Reached either from a set of stairs running up from the wall’s inside or from a built-in tower. Can also be the fighting area on a tower as well.
Bastion or Bulwark- a structure projecting at the end of the curtain wall or at the junction of 2 walls. Usually situated at each corner of a curtain wall. Though could be placed in the middle if the walls were long. Allowed the defenders to cover dead ground (blind spots where attackers can’t be seen or fired upon) and provide crossfire for the curtain wall and adjacent bastions. Can consist of a tower or turret.

Batters- a section at a castle wall’s base that’s angled in such a way to make dropped stones bounce away from the curtain wall and into the enemy. Also add strength to the wall walk’s base.

Buttresses- a rectangular masonry projections used as additional outside strength and support for walls. Become thinner towards the top. Prominently featured in Gothic cathedrals like Notre Dame.

Chemin-de-Ronde- a walk-walk extending all the way around a castle.

Chemise Wall- wall formed by a series of interlinked or overlapping semicircular bastions.

Citadel- the innermost curtain wall of a concentric castle. Had walls higher than the rest and was the last line of defense before the keep itself.

Corbel- a stone bracket projecting from a wall or corner that supports a main floor or other structure’s weight. Often used for turrets.

Cornice- a decorative projection along the top of a wall.

Counterguard- a long near-triangular free-standing fortification within the moat.
Crenels, Embrasures, or Wheelers- small openings in crenellation that’s splayed on the inside, allowing the archer to move into the arrow slit space and get a better view.

Cross-Wall- an internal dividing stone wall in the keep providing extra strength and a platform for wooden floors. Also served as a barrier at times when the keep had been invaded.

Curtain Wall or Enceinte- a surrounding outer stone wall around the castle connecting the towers and other fortifications. Was designed to protect the castle. Can be 8-20 feet wide, up to 45 feet high and 1,500 feet long.

Flying Buttresses- masonry projections used to spread and support the weight of tall walls by transferring force directly to the ground. Were often elaborately designed, appearing to dart and sweep around each building, giving a sense of movement and flight. Usually decorated with intricate carvings giving a sense of grandeur and importance.

Garderobe- a room projecting from a wall that served as a toilet the family’s clothes. A hole in the floor allow wastes to drop below. Had chutes for discharge which often led to the castle moats and had iron bars to prevent entry from attackers.

Glacis- an angling of the curtain wall along the vertical plane that allows the wall to deflect some or all the force of rocks or other missiles thrown from a siege engine or cannon balls fired from siege cannons.

Hoardings or Brattices- wooden fortifications added to the crenellations and towers to provide additional protection to the castle’s defenders. They were removable and provided overhead cover. Also provided a walkway outside the crenellations facilitating the dropping of stones and hot liquids on attackers.

Hoarding Holes- holes in the castle walls to support the hoarding.

Inner Curtain Wall- defensive wall within a castle dividing the inner area into 2 or more defensive areas.

Lunette- a fortification shaped like a half-moon or arrowhead which was similar to a bastion except that it didn’t have wings connecting to a castle’s wall and the back was generally open. Can be its own structure or connected to a curtain wall like a bastion.
Machicolations- permanent stone additions to a castle’s battlement which provided better cover for defenders inside the castle, allowing them to drop items like boiling oil, hot lead, dead animals, human excrement, and rocks on attackers. Most often located in places that would be commonly attacked like near the main entrance.

Oriel Window- a window or set of windows sticking out from a building like bay windows. Made of stone or wood. Often had corbels underneath to support them.

Orillion- an arrowhead bastion.

Palisade- a sturdy wooden fence built to enclose a site until a permanent stone wall could be constructed. Can be as high as 10 feet tall.

Pitatta Forma- a fortification structure protecting the curtain wall between 2 bastions. It’s square or rectangular in plan but takes the form of a small tetrahedral bastion.

Plinth- a wall’s projecting base.

Postern or Sally Port- a small secondary gate located in the curtain wall’s back, which mostly functioned as a backdoor entrance or exit. Was connected to a small guard room near the bailey. Was often in a concealed location which allowed occupants to come and go inconspicuously. If possible, it could be built on a cliff, only accessible by footpath. During a siege a postern could act as a secret exit for troops to pass through besiegers or send out a messenger. Was firmly barricaded during conflict and people sometimes used a password to enter. Used by tradesmen and servants during peacetime. Designed for only one unmounted person could go through at a time.

Putlog Holes- castle wall holes to support scaffolding.

Rampart- a defensive wall of stone and mounds of earth that can be built quickly for early medieval castles. Later replaced by battlements.

Rear Arch- arch on an inner wall’s side.

Relieving Arch- an arch built in a wall to relieve thrust on another opening.

Respond- a half-pier bonded into a wall to carry an arch.

Redan- a small ravelin, derived from the lunette but had shorter sides. Was often made of earthwork but could comprise of stone and other materials. Could be its own structure or connected to a curtain wall like a bastion.

Rubble Core- a filling between the outer and inner wall parts.

Shield Wall- an exceptionally thick wall protecting the castle on its most vulnerable side.
Talus- a slope on the curtain wall that inhibited an attacker’s ability to reach the wall with a siege tower. Since a tower’s ramp wasn’t enough. Also provided a strong foundation to help support a wall against undermining.

Battlements

Arrow Loops, Arrow Slits, or Loopholes- thin slots in the walls and structures used to shoot arrows through. Came in a variety of shapes and sizes, usually depending on the weapons fired from it. Low and narrow arrow slits were suited for crossbows. High and wide arrow slits were built for longbows, which can be as high as 9 feet. But common designs are key holes, vertical slits, or crosses which allow the archer to fire his weapon with a great amount of protection.

Battlement, Rampart, or Crenellation- a defensive, outside top wall that has a broad top with a walkway and a typically stone parapet. Notched wall consists of alternate crenels (openings) and merlons (square sawteeth) to give castle defenders a position to fight or fire through as well enough protection to reload.

Fausse Braie- an exterior battlement, outside and parallel to the main battlement and considerably below its level.

Finial- a slender piece of stone used to decorate the merlon tops.

Merlons- upward square sawteeth of a battlement. Often pierced with arrow slits for observation and fire. Are usually rectangular in medieval Europe but can also appear in a swallow-tail form along with other shapes. Also have a secondary decorative purpose by giving the castle a distinct castle like appearance you find in storybooks.

Oilette- a round opening at a loophole’s base to help archers to easily aim a shot.

Parados- a low wall on a main wall’s inner side.

Parapet- a barrier at the edge of a roof, terrace, walkway, or other structure. Often used to defend a castle from military attack as a low defensive wall at shoulder or head height.