How Medieval Castle Towers Actually Worked

How castle towers evolved from the central bergfried to wall towers with crenellations, arrow loops, and hoardings, then gun loops and bastions as gunpowder changed warfare.

Key Takeaways

Castle towers evolved in response to changing military technology, from crossbows to gunpowder.
Regional differences meant German castles relied on the bergfried longer than other European regions.
Defensive features shifted from height advantage and crenellations to protected firing positions and artillery resistance.
Gunpowder ultimately forced castles toward fundamentally new designs such as bastions.

What the video covers

Castle towers changed radically over the Middle Ages and beyond to adapt to new warfare.
The video focuses on wall towers in Germanic (Central European) castles, distinct from main keeps like the English keep, French donjon, and German bergfried.
Most German castles lacked wall towers until the 12th or 13th century; the bergfried was the central defensive element.
Passive defenses such as elevated positions, moats, and strong walls were favored over active ones like wall towers.
The spread of the crossbow in the 1200s encouraged a more active defense of the castle perimeter.
Early wall towers were often square or rectangular, with crenellations, small arrow slits, and height advantage for defenders.
Wooden hoardings were added atop towers to allow defenders to shoot or drop projectiles at the base without leaning out.
Gunpowder arrived in the 14th century, leading to gun loops with round openings and aiming slits in the 15th century.
Overhanging stone battlements with machicolations replaced wooden hoardings, offering protection from cannon fire.
Battery towers and rondels were developed for artillery, but their rounded or open designs created vulnerabilities that drove radical change in castle architecture toward the bastion.

Chapters

Why did most German castles lack wall towers for so long?

The video explains that German castles relied on a centralized defensive doctrine built around the bergfried, a single large tower. The surrounding wall was seen as an additional obstacle rather than a place to fight, and building extra towers was costly, so wall towers were not considered necessary until the 12th or 13th century, and in many cases later.

What were hoardings and why were they useful?

Hoardings were wooden structures added to the tops of towers that projected outward. A gap between the structure and the tower wall let defenders see and shoot at enemies at the base without leaning out, keeping them protected from the front.

How did gunpowder change the design of castle towers?

Gunpowder led to gun loops with round openings for gun barrels and aiming slits, plus overhanging stone battlements with machicolations. These offered better passive resistance against cannon fire and let defenders shoot or drop rocks at attackers near the wall base.

Full Transcript — Download SRT & Markdown

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This is what most people usually imagine when they think of a castle tower, but in a lot of historical castles, you won't find a single tower with this classic medieval design we all know and love. During the Middle Ages and beyond, castles underwent radical changes to adapt to new styles of warfare, and their towers changed with them. Today, we are going to take a look at the development of castle towers and find out how they evolved over time to eventually turn into something completely different. Welcome to Castellum.

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castles underwent radical changes to adapt to new styles of warfare and their towers changed with them. Today, we are going to take a look at the development of castle towers and find out how they evolved over time to eventually turn

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They have to be viewed separately from the large main tower a castle might have, such as an English keep, a French donjon, or a German bergfried. Even though they can be quite similar in design and function, these structures

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In this video, I'm going to focus on wall towers, which are towers placed around the castle's enclosing walls to defend it from enemies. They have to be viewed separately from the large main tower a castle might have, such as an English keep, a French donjon, or a German bergfried. Even though they can be quite similar in design and function, these structures should be treated as their own topic since they evolved a little differently from wall towers.

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from those in another region. On my channel, I mainly focus on what I call Germanic castles, which are found throughout Central Europe, such as in Germany, Austria, or Bohemia.

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Castles can be quite diverse and developed a lot of variation throughout Europe, so the wall towers in one region might be completely different from those in another region. On my channel, I mainly focus on what I call Germanic castles, which are found throughout Central Europe, such as in Germany, Austria, or Bohemia.

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Although wall towers were definitely known from remaining Roman city walls and were widespread, for example, in France, most German castles simply didn't have any up until the 12th or 13th century, and many cases even later.

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For a long time, it was not really common for castles in Germanic regions to have towers along the walls. Although wall towers were definitely known from remaining Roman city walls and were widespread, for example, in France, most German castles simply didn't have any up until the 12th or 13th century, and in many cases even later.

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The surrounding wall was merely considered an additional obstacle with the giant bergfried being the truly defendable part of the castle. Maybe it's due to the centralized defensive doctrine that constructing additional wall towers wasn't seen as necessary.

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Instead, the bergfried, a single large and high tower, was the main focus of the castle's defense and its strongest building. The surrounding wall was merely considered an additional obstacle, with the giant bergfried being the truly defendable part of the castle. Maybe it's due to the centralized defensive doctrine that constructing additional wall towers wasn't seen as necessary.

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Moreover, building a castle was quite an expensive endeavor often undertaken on a tight budget. As a result, the bergfried remained the central and most crucial element of a castle's defensive architecture for centuries.

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During this period, castles relied more on passive defensive features like elevated positions, extensive moats, and strong walls rather than active defenses such as wall towers or arrow loops. Moreover, building a castle was quite an expensive endeavor, often undertaken on a tight budget. As a result, the bergfried remained the central and most crucial element of a castle's defensive architecture for centuries.

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perimeter instead of the old strategy of just retreating into a strong building and preventing the enemy from entering.

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But over time, castles grew larger and new military tactics required more complex defensive concepts. Maybe it was the continuous improvement and widespread adoption of the crossbow in the 1200s that led to a new, more active approach to defending the castle perimeter, instead of the old strategy of just retreating into a strong building and preventing the enemy from entering.

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Following the military strategies at the time, the defenders were primarily placed on a platform on top of the tower. The main strength of such a tower came from the height advantage it gave its occupants. They could shoot their

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New towers along walls started to be constructed, with square or rectangular towers being by far the most common, but a lot of round towers can also be found.

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Those towers very often feature crenellations, which are elevated parts of the wall that allow the defenders to take cover from enemy projectiles.

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Following the military strategies of the time, the defenders were primarily placed on a platform on top of the tower. The main strength of such a tower came from the height advantage it gave its occupants. They could shoot their crossbows further from this elevated spot and were at the same time very hard to reach for the attackers. Stones dropped from greater height also developed much more force on impact.

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century. Small slit-shaped openings in the tower walls were usually only intended to let light and air into the dark interior rooms. Any larger windows could only be found on the upper stories to prevent enemies from utilizing them to climb into the castle. Over time,

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Those towers very often feature crenellations, which are elevated parts of the wall that allow the defenders to take cover from enemy projectiles.

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They featured small windows or arrow slits which could be used by the defenders to shoot at enemies with their crossbows while staying safe behind cover. Those small openings provided much better protection from enemy projectiles compared to the larger space

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Depending on the climate, roofs were also built to protect the platform from bad weather. These early towers often did not have arrow loops at first, as they were not really common in Central Europe until the second half of the 13th century. Small slit-shaped openings in the tower walls were usually only intended to let light and air into the dark interior rooms. Any larger windows could only be found on the upper stories to prevent enemies from utilizing them to climb into the castle. Over time, additional wooden structures started to be placed on the tops of towers to increase their defensive value.

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having to lean out like you would have to on a crenellated tower. Instead, they would be completely protected from the front. It also became more important to protrude the tower outwards to allow for effective flanking fire. Arrow slits

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They featured small windows or arrow slits, which could be used by the defenders to shoot at enemies with their crossbows while staying safe behind cover. Those small openings provided much better protection from enemy projectiles compared to the larger space between regular crenellations. A gap between the wooden structure and the actual tower wall allowed the defenders to see the tower space and eliminate blind spots. This enabled them to shoot straight down or throw rocks at enemies close to the base of the tower without having to lean out, like you would have to on a crenellated tower. Instead, they would be completely protected from the front.

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During the 14th century, gunpowder was first introduced in many regions of Europe. While somewhat ineffective in the beginning, handguns and early cannons slowly developed into a feared weapon of war at the beginning of the 15th century. To deal with the emerging

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It also became more important to protrude the tower outwards to allow for effective flanking fire. Arrow slits were added on different levels so multiple defenders could fight simultaneously. From their protected position, they were able to safely shoot along the walls and cover all sides of the approach from multiple angles.

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Compared to the older arrow loops for crossbows, gun loops came in a much wider variety of shapes, sometimes quite experimental. They often featured a round opening to accommodate the gun barrel combined with a vision slit for aiming. Overhanging stone battlements

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During the 14th century, gunpowder was first introduced in many regions of Europe. While somewhat ineffective in the beginning, handguns and early cannons slowly developed into a feared weapon of war at the beginning of the 15th century. To deal with the emerging threat of gunpowder weapons, castle towers had to be adapted, and new gun loops specifically designed for use with firearms were added to the towers.

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close to the foot of the wall while staying safe from enemy fire. Although stone construction was technically stronger, thick wooden battlements continued to be used alongside stone machicolations for a long time because they were lighter, cheaper, and could

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Compared to the older arrow loops for crossbows, gun loops came in a much wider variety of shapes, sometimes quite experimental. They often featured a round opening to accommodate the gun barrel, combined with a vision slit for aiming. Overhanging stone battlements were also becoming increasingly popular during this period. They often rested on stone corbels and featured so-called machicolations, which are openings in the floor. Like the earlier wooden hoardings, those gaps could be used to shoot down or throw rocks at attackers close to the foot of the wall while staying safe from enemy fire.

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structurally weak when being bombarded with early cannons. To counter the rising threat of gunpowder artillery in the late 15th century, new towers were built rather low, often only one story higher than the wall itself. This gave enemy cannons

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Although stone construction was technically stronger, thick wooden battlements continued to be used alongside stone machicolations for a long time because they were lighter, cheaper, and could also absorb gunshots. The continuous development of gunpowder weapons led to a radical change in defensive architecture. Traditionally, towers relied on their height to give the defenders the best possible advantage point and were built relatively tall and slender. But this made them structurally weak when bombarded with early cannons. To counter the rising threat of gunpowder artillery in the late 15th century, new towers were built rather low, often only one story higher than the wall itself. This gave enemy cannons a smaller target and at the same time provided much better stability. The thickness of the walls was also increased to resist bombardment.

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tower also increased the angles of fire for the defenders, which now primarily relied on guns to fight off enemies. A large number of dedicated gun loops for arquebuses and heavy wall guns were placed on multiple stories of the tower.

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Rounded tower designs became by far the most common, as they could deflect cannonballs much more easily. The round shape of the tower also increased the angles of fire for the defenders, who now primarily relied on guns to fight off enemies. A large number of dedicated gun loops for arquebuses and heavy wall guns were placed on multiple stories of the tower. Instead of being isolated strongpoints along the wall, towers now were a part of complex systems designed to allow flanking fire and maximum area coverage.

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While the gun towers of the 15th century provided much more passive resistance against cannon fire, their active defense still mostly focused on fighting off enemy infantry with the use of handheld firearms, such as arquebuses or wall guns. But, the rapid improvement in

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While the gun towers of the 15th century provided much more passive resistance against cannon fire, their active defense still mostly focused on fighting off enemy infantry with the use of handheld firearms, such as arquebuses or wall guns. But the rapid improvement in artillery technology and increasing range of siege guns meant that castles needed their own cannons to counter enemy bombardment. To provide firing positions for the new heavy cannons, castle towers turned

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Large gun ports allowed the defenders to fire the cannons from inside the tower while being well protected by very thick walls. The round shape of the tower allowed them to shoot into every direction and cover a large area with

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just a few guns. Because of their enormous weight, the heaviest guns were placed on the lower level of the tower.

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Being close to the ground not only made moving them in and out of the tower much easier, but also allowed lighter ceilings on the upper stories, since they would not have to support the weight of the heavy cannons. Lighter

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cannons that had less range, but could be loaded and aimed much quicker, were placed on the middle levels of the tower. To repel infantry attacks, many towers also had additional gun loops for arquebuses and muskets, often at the top

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level. The trend towards heavier cannons and more massive firing positions continued through the 16th century and led to modern defensive designs that put an even stronger emphasis on low profile, but very massively built structures. To enable the positioning of

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more heavy cannons within castles, large artillery positions called rondels became very common during the 16th century. They ditched the additional floors and range advantage a tower offers in favor of a lower, but more massive construction that allowed for

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heavy guns to be placed on their top platform. The round or D-shaped buildings are usually the same height as the connecting walls, which gave enemy artillery less area to attack. Rondels were often quite large in diameter, so many cannons could be operated at the

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same time. Their open platform prevented the build-up of gunpowder smoke and provided better visibility of the surroundings. To further increase firepower, many rondels featured an additional platform for cannons on ground level. Others were filled with earth instead, which made them almost

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indestructible by enemy cannons. While both battery towers and rondels are quite strong defenses, they have one fatal flaw that posed a huge problem for the defenders and led to a very radical change in castle architecture. Over the course of the 16th century, flanking

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fire became one of the most important parts of castle defense. Defensive positions had to be able to cover and support each other with cannon fire, so enemies would be shot at from multiple angles. This would make approaching their walls and towers extremely

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dangerous for the enemy. But round shapes led to large blind spots in front of the towers and rondels. This created dead spaces that could not be seen and fired upon from the other towers, giving attackers the chance to get close to the

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wall unharmed. To counter this flaw, Italian architects came up with the idea of using angled shapes instead of round ones. This eliminated any blind spots, allowing the defenders to see anything that goes on in front of the walls. The

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so-called bastions are pretty resistant to cannon fire, since the angles also meant that cannon shots would be deflected to the side and lose a lot of energy, similar to a round shape. The two fronts are called faces and were

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used to place long-range cannons to counter enemy artillery positions. The shorter sides are called flanks and would be used to fire along the walls to prevent scaling with ladders. The open and linear design of meant that there was a lot of space for

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cannons compared to the rather cramped round tower. Many bastions also featured bomb-proof casemates with large openings for cannons on a lower level where additional artillery pieces could fire from a protected position within the walls. Bastions were the dominant form

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of defensive architecture in the 17th century, but rondels continued to be used alongside them. But even though modern bastions and rondels were much more suitable for modern artillery warfare, you have to keep in mind that it was extremely expensive to build

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those kinds of fortifications, much more so than traditional castle towers. Many castle owners did not have the funds to convert their castles into modern fortresses, so they would just continue to use what they already had, maybe with slight modifications such as changing

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the crenellations to gun loops and creating openings for cannons in their medieval towers. Castles also grew and expanded over centuries, so it's really common to find artillery fortifications defending the outside perimeter and a high medieval bergfried still dominating

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the inner bailey. A bergfried still could be used as a lookout or to place light cannons, after all. If you would like to learn more about bergfrieds and keeps, check out my video about castle towers in the game Kingdom Come:

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Deliverance, too. It's pretty realistic. Thank you for watching. Please consider leaving a like and subscribing to my channel if you are interested in castles and fortresses. See you soon.

Topics:castle towersmedieval architecturebergfriedwall towerscrenellationsarrow loopsgun loopsmachicolationsgunpowder warfareGermanic castles

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