Types of Castles (TCG)

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Though the player need not follow any one castle discipline in designing his keep, there are a number of design types that he should be aware of. There are three basic human castle designs, which include the Motte and Bailey, the Curtain Wall Defense, and the Concentric Castle. The style in which the DM desires to play his campaign, will ultimately determine exactly which design type or parameters the player will be able use in building his castle.
There are several distinct phases or technological achievements in building castles. The DM may stipulate from which technological level, as described below, the player can choose the design specifications of his keep. Tech levels will be later used in describing castle modules in which the player uses to construct his castle.
 Technological Levels
TL	Remarks
1 	Early Wooden Construction
2 	Advanced Wooden Construction
3 	Early Stone Construction
4 	Advanced Stone Construction
5 	Early Gatekeeps & Hoardings
6 	Advanced Gatekeeps & Machicolations
7 	Grand Gatekeeps
8 	Full Concentric Castles
Motte and Bailey Castles: The motte and bailey castle of the eleventh and twelfth centuries consisted of a large mound of earth or a natural hill (the motte) topped by a wooden keep or tower surrounded by a palisade and ditch. In many cases this was surrounded by a number of buildings (the bailey) used as accommodations for guests or extensions of the family (older son, brother, mother, etc.), servant quarters, guard towers or posts. troop barracks, stables, livestock pens, or storage buildings. The whole area was defended by another palisade and ditch. The palisade of the bailey often continued up the motte to connect with the palisade there. Entrance to the castle was through an outer drawbridge and a gatekeep which normally consisted of two sturdy towers flanking the drawbridge with winches within controlling the lowering and raising of either a wooden or partial metal gate.
This basic defense system proved strong enough until the early fourteenth century. But the castle design had two major flaws. the first was in its series of barriers (the palisades and ditches), which could not support each other and allowed the attackers to concentrate their forces against each barrier one at a time. The second flaw. and one that would soon be remedied, was the construction of the castle from wood, which tended to make it easy prey to fire. Nonetheless, castles of motte and bailey construction were built and inhabited throughout medieval Europe for several centuries.
The motte and bailey design began to change as early as the twelfth century by first replacing the wooden tower on the motte with a stone tower or building. Later the inner and outer bailey was changed over to stone as well. Subsequently, the baileys accrued battlements in the form of arrow slits, guard towers, and trap doors from which rocks or boiling oil could be rained down on invaders.
The castle proper, the tower on the motte, was replaced by two basic types of keeps, sometimes referred to as donjons. The easiest and cheapest type of donjon was the shell keep, which was simply a stone wall following the line of the motte palisade, with housing and other buildings taking the place of the tower, and using the stone palisade as their outer wall. With such a construction an open courtyard in the center of the motte appeared. The main advantage to the shell keep was that it could be quickly added to or taken down. and that its weight was evenly distributed over the hill so that it could be constructed on artificial mounds of dirt with little chance of the walls crumbling under their own weight.
The other type of donjon that appeared from the motte and bailey design was the stone tower. These massive buildings of stone were so heavy that they had to be built on natural hills, since constructed mottes tended to shift and crack. the walls of the stone tower. When a stone tower was built, and no suitable motte was available, the engineers sometimes built the tower on flat ground then buried half of the tower, creating, in essence, an artificial motte. The walls of a stone tower averaged 15 feet thick and stood as high as 50 feet. Supported by large stone or heavy wood buttresses, the tower widened at the base to protect itself from the onslaught of a ram or pick. An average stone tower would measure approximately 3,600 square feet, or an average of 60 feet on a side. At the lowest levels, there would be numerous windows and slits used (at first) for ventilation and light. Later, these became arrow slits and assumed a vital role in the keep's defenses. On the second and third floors of stone towers, the air slits enlarged to about two feet wide and four feet tall, but rarely were they left open (more often than not, they were. heavily barred and shuttered).
Entrances to a stone tower were either through a broad door at the bottom level, or through a more personable entry on the second floor. The second floor entrances, however, were accessible only by a narrow stairwell that wound clockwise to the doorway. In either case, many of the stone towers had a small gatekeep constructed to guard the entrances of both doors. Within the stone tower the design followed quite similar to the original wooden towers of earlier centuries, with a strong cross wall so that, should the entrance to the donjon be forced, the defenders could retire behind yet another line of defense. The cross wall, on the first and second floor, was well built and had only one door joining the tower together. As with its outer spiral staircase to the main door of the keep, all internal staircases wound clockwise giving the defenders room to swing their swords freely, while the attackers had a tough time using their swords and shields (assuming that they were right handed, of course).
The greatest weakness of the stone tower was its squared corners, which were easily broken by siege weapons and were quite difficult to defend (the defenders had to expose most of their bodies to shoot at invaders at the base of the wall). By the beginning of the thirteenth century this problem was slightly alleviated by rounding the corners of the building and constructing a cylindrical keep. However, just as the design started to take hold across Europe, other advances beyond the fortification of the keep itself, forever changed the view that the stone tower was the ultimate defense of a castle, and only a few rounded stone towers were built.
Curtain Wall Defenses: Until the mid-thirteenth century almost all the castles of Europe were built with the motte and bailey design, a defense system based on uncoordinated walls and towers to wear the attacker down and permit the defender many opportunities to strike back. This rarely worked, however, and the attacker more often than not simply tackled each wall separately, reducing it to rubble and then moving on to the next barrier. As time went by, fortification design techniques from the east spilled into Europe. Many new features began to be added to the existing castles and many totally new designs began to appear. The significance began to shift away from the supposedly impregnable donjon to the bailey walls, for it was wiser to keep the attackers from breaching the outer most wall, then to let him in to ravage and plunder the many buildings and storage houses on the inside of the outer bailey.
The main improvements to the fortified walls were measures allowing cover for archers, modified battlements to withstand siege engines and moving ramparts, and wide walkways (catwalks) giving free movement of large numbers of troops and knights on the walls. There still existed the main problem of sappers (miners) and siege weapons at the base of the bailey. The only solution to keeping the attackers away from the bailey wall, was not to allow the attackers to get close. This was solved by the invention and use of the merlon, which was a raised portion of a wall, with arrow slits, murder holes, and machicolations enabling full scale bombardment of warriors at the base of the fortification.
Another way to protect the wall from siege engines like the ram, pick, or screw was through the use of brattices and hoardings, a covered wooden platform built on the battlements to allow missiles and stones to be dropped through slots in the floor. These simple devices had been used since the early twelfth century, but had been overlooked because they tended to be easy targets for catapults and ballista-like weapons, but the use of the merlon and hoardings together proved an effective way of keeping attackers at bay.
The greatest advancement in castle design and fortification was the use of the flanking tower, which first began to appear in the late twelfth to early thirteenth century in parts of southern Europe. Before this time, square towers or merlons had been set even with the outer bailey, but by extending several towers outward, away from the rest of the wall, it allowed the defenders to fire from arrow slits on the sides of the towers along the length of the castle's outer wall. This meant that the warrior did not have to expose his body to attacking archers in an attempt to shoot invaders nearing the wall.
Each flanking tower also provided cross fire for its neighbors. When the outer wall was breached, it cornered or contained the invading army into distinct regions. The first flanking towers were three-sided, with their backs open to the inner bailey, so that in the event the tower was captured by the invading force, they would prove of little worth. As time went by, the flanking towers became square and protected on all sides.
The advancements in the ability to make circular keeps also came to apply to the construction of flanking towers, and by the close of the thirteenth century most new flanking towers were cylindrical.
Concentric Castles: The greatest period in castle development occurred during the last days of the thirteenth century and the beginning of the fourteenth with the advancement of the concentric castle in Europe. The castles origins follows the crusaders back to the distant lands of Syria and consisted of a number of circuit walls and towers, usually quadrangular in plan, surrounded by another lower wall with its own flanking towers. The area between these two walls, usually only a few tens of feet apart, was divided by a number of short cross walls that segmented the tight inner courtyard; thus, if any force penetrated the first wall, they would be confined to a small specific area and immediately confronted with a like secondary defensive wall. The area in the confined space became known as the killing ground, since almost all of the initial troops into this small area were decimated by archers and falling stones from the second wall.
By the end of the fourteenth century castles were so strongly defended, that attacking them was nearly out of the question. The only option open then, was a long and drawn out siege where machines of war sat idle until famine and pestilence killed all within the massive stone walls.
Thus, the castle slowly faded from the focal point of war and lost its well known role as the defender of peasants and the gentry.
The Gatekeep: The player should take note of one vital aspect of castle design-the gatekeep. During the eleventh and most of the twelfth centuries, the gatekeep (a structure which protected the entrance way into the castle) consisted of two square towers on each side of the bailey wall. Towards the thirteenth century this was replaced by four towers, two at each end of the entrance way. connected by a short stone wall that provided excellent protection and bottled up the enemy in the event that the gatekeep was breached.
At this time however, the four towers were still squared block buildings. Drawing into the mid-thirteenth century these squared towers evolved into rounded or circular towers. By the fourteenth century the four towers had been. connected by short hallways allowing freedom and security of troops within the guarded gatekeep. Now, troops were able to move freely from one tower to another without fear of being struck by enemy artillery.
With the invention and use of a guarded gatekeep, these buildings took on a more important role in fighting off invaders. Since they stood, literally, at the doorstep of the castle, the defenders inside had opportunities to sally forth outside the castle. In this way, they engaged the enemy, yet could quickly withdraw from the field of battle without endangering the castle itself.
As this principle of design took hold in Europe, additional defenses, called barbicans, were of ten built to protect the gatehouse. The barbican acted as a miniature bailey, extending walls at right angles from the castle's fortifications. Any attack to the gatehouse then had to pass through a very narrow cleft, from which artillery and archers from within the gatekeep could rain death down upon the intruders. As time went by, these outer bailey walls also took on stone towers, mottes, ditches. drawbridges, or water filled moats to further strengthen the entrance way into the castle proper.