The Castle – Part 2 Design and Evolution
Having established that castles had two main purposes, one being defense, the other being offensive or terror weapons, it follows that one should also look at the evolution of these fantastic structures or at the very least their beginnings and the major forms they took over the succeeding centuries.
In case I wasn’t clear enough in the first part, I am using what a layman would consider a castle. This is different from what most in the academic world would use for a definition. A castle is supposed to be a fortified private residence of someone, a king, the nobility, bishops, or other principle officers inhabiting the structure on their behalf. This is distinct from a fortress, which is often indistinguishable from a castle in appearance, but these would, by definition, not have as one of their primary functions residential accommodations. The word citadel refers to either a castle, a fortress or a fortress that includes a castle, meant to defend a town or city, often in congress with city walls.
I am counting all of those things as castles, just so we are clear. The distinctions are kind of watery and really don’t have much meaning outside of academia. At any rate…
The first “castles” in Europe were really built by the Romans. I mentioned the roman fortress in Jerusalem as an example before. In reality most of these structures were meant to house and supply soldiers rather than provide any major offensive or defensive support, which is exceedingly similar to military forts today. The last place you would want to try and defend would be Fort Benning or any other modern forts, at least in any serious way.
Within the ruins of many of these roman forts, after the fall of the Western Empire, we start to see keeps built. Keeps being a castle within a castle, a fortified structure inside a fortified structure, with independent defenses of it’s own. A new type of structure was being invented though, the first purpose built castles, of the Motte and Bailey type. You couldn’t get any simpler than this. You can in the picture the lower fortified bailey, overlooked by a motte, or raised earthwork, with it’s keep atop of it. As I mentioned, the keep has it’s own independent defenses, again shown in the picture to the left. You can see the separate wooden palisades around both. It was also possible for there to be more than one Bailey. Windsor Castle is an excellent example of a later, masonry motte and bailey structure, with two, rather than one, bailey. The Wiki page has an okay picture if you are interested, but I can’t find any better ones.
From the 10th century on, this was the best game in town. When the Normans invaded and conquered England in 1066, William the Conqueror and his Norman Lords, built scores of these across the country, and used them to great effect to bring the populace under submission and also to defend strategic locations and resources, such as London, which may have had as many as 12 of these motte and bailey structures encircling it.
This design was an elegant solution to a great many military problems, but it wasn’t perfect. You will recall these things are just made out of wood, which makes them so easy to burn down, that even a child could do it, and I’m sure some did. Furthermore, while the motte provides a sort of tower from which to defend, other such locations are found severely wanting. Any towers that were built aside from the typical gatehouse and motte were low constructions suffering the same limitations of the wooden keep and palisades, fire sucks. While a near universal feature was also a ditch and/or berm outside the palisade, somewhat analogous to the tank traps of WW1 and 2, they are still easy to overcome.
Most had moats, and a moat is not always water filled. The ditches and berms mentioned above were indeed moats, albeit dry ones. Water filled moats, oddly enough, require a source of water, but are remarkably effective if one can be had. Its hard to walk or swim with weapons, to say nothing about the difficulties of using siege engines in later centuries or even ladders in contemporary ones. There were, for lack of a better term, “artificial” mottes built. Now mottes were almost always artificial, but I mean a tall structure by virtue of building design, rather than a squat one on top of a mound of earth. The Tower of London is a great example of this concept. As far as I am aware, no period examples exist of an original wooden Motte and Bailey castle. Wood doesn’t last forever you know (for that matter neither does stone), so in time, many would be constructed from wood then converted to masonry as time passed.
(It bears mention that castle waste of all kinds was often… uh… “deposited” in the castles moat, making it even more unlikely for attackers to venture into it.)
These upgrades led to the construction of a “new” sort of castle, sometimes known as a “stone keep castle”. The only major differences were their construction out of stone and as a result, the keep itself became fortified, as opposed to surrounding the keep with a separate wall, palisade or stockade.
Motte and Bailey type castles started to die out in the 11th and 12th centuries, and were generally not constructed at all by the 13th century. Men had returned from the Holy Land with new ideas about castle building, concentric fortification being perhaps the biggest game changer.
Note the taller inner curtain wall and the lower outer one (called a barbican). This design allows defenders to man two or more layers and avoid hitting men with arrows or what-have-you stationed at or on other walls further out. Those laying siege or simply attacking the castle have to overcome two or more walls, whether by direct assault and scaling of them, or by undermining. Concentric castles that also have a water filled moat were immune in any practical sense to undermining, what with saturated soil not supporting tunnels well and even the castles without wet moats are likely to foil mining attempts by the weight of the barbican collapsing the tunnel beneath. Also common, more so with a dry moat, was a significant foundation of stone beneath walls, making mining even harder to pull off. The advent of concentric walls effectively ended any army having the ability to take a castle by force, leaving only deception, bribery and starvation as means of taking a castle.
Murder holes, arrow slits, bent entrances, caltrops, and lots of other innovations, whether recycled from antiquity or not, also led to castles becoming invincible (until cannon were invented) to most everything. The exceptions I mentioned were all results of human weakness rather than faults in castle design or strategic or tactical errors made by the defenders. There were exceptions, many of them, castles could still be taken, but it had become such a difficult feat, that it was safer to simply go around the castle or lay siege. As besiegers often discovered, they would lose more men to sickness, than to military action. Cholera, infuenza, typhoid, smallpox, etc, all were as hazardous or more so to both the besieged and the besiegers than pitched battle would be.
Considering modern humans** had been around for 15,000 years, there was an astounding flaw in practically all castles, citadels, and so on. This flaw was because of towers being round. The problem with round, square amd most other shaped towers, is that they create “dead zones”, where little or no fire can be concentrated and so giving an attacker a safe place to breach the walls by means of ladders, siege engines, pick axes, and whatever else you can think of.
This incredible flaw, while usually fairly difficult to exploit for any great effect, wasn’t corrected until the late 15th or 16th centuries. Castles were becoming burdensome toward the end of the 15th century. Many, if not most, nobles, kings, queens, bishops, etc, had started building unfortified manor houses, which were much cheaper and far more comfortable to reside in. Gunpowder was rapidly making traditional castles obsolete, and so lacking much effectiveness, many were sold, “mined” for their stone (ala the roman colosseum), or just re-purposed to be solely administrative structures.
Gun powder did resolve this flaw. Star forts were designed to somewhat counter the destructive power of cannon and to an extent, they were effective at doing so. Unfortunately, it was cutting off your nose to spite your face, because some of the characteristics a star fort had to counter artillery, made these forts more vulnerable to infantry, even with the advent of the pointed towers with overlapping fields of fire.
6 of one, half a dozen of the other. Gunpowder had effectively killed castles. It was thus made economically unfeasible for anyone to build a defensive structure that conferred any significant defensive benefits. Indeed, with the advent of the “New Model Army” in 17th century Britain and elsewhere, warfare changed forever. Castles were relegated to the pages of history, becoming a novelty at worst and a fixture in “fairy tales” at best.
Stay tuned for part 3.
** Modern humans meaning we had established settlements, not that we are of a species that arose only since that time. I stick it at 15,000 years ago, others may disagree, but it doesn’t really matter. The way I see it is that we became a different “cultural species” when we started forming settlements of a given size. So I suppose I am saying we are a different “species”.