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’ thick and stood as high as 50’. 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’ 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.