Military Architecture in England During the Middle Ages

by A. Hamilton Thompson

Coucy

The cylindrical form of donjon was brought to perfection in France under Philip Augustus (1180-1223). At Gisors, which came into his hands in 1193, he built a new circular tower on the line of the curtain, which superseded Henry II.’s octagonal tower on the mount. His fortification of Gisors led directly to the building of Château-Gaillard by Richard I., to cover the approach from French territory to Rouen.[208] But in 1204 the capture of this great stronghold delivered Rouen into Philip’s hands; and in 1207 he built the donjon, now known as the Tour Jeanne d’Arc, at Rouen. Here we meet with the tower vaulted from basement to roof, with a strongly defended entrance at the level of the ward in which it stands, of which the most perfect example is found at Coucy.[209] Coucy, the work of a powerful vassal of the crown of France, represents a degree of scientific fortification to which none of our cylindrical donjons attains. The castle was constructed, like Conway at a later period, in connection with the defences of a walled town.[210] It consists of two wards, a large outer ward or base-court and an inner ward of irregular shape, with four straight sides of unequal length and round towers at the angles. In the middle of the east side, between the two wards, is the donjon ([177]), a cylinder of some 200 feet high—90 feet higher than the tower of Rochester. It stands isolated from the curtain of the inner ward, from the line of which about one-third of its circumference projects, and is surrounded by a ditch, originally paved with stone. To this ditch there was no external access. On the outer edge of the ditch, joining the east curtain of the inner ward at two points, was a strong wall or chemise. Outside this was the ditch dividing the inner ward from the base-court. Within the inner ward, a low wall took the place of the chemise of the donjon, and access to the tower was provided by a bridge across the stone-flagged ditch. The bridge was worked by a windlass, and, when not in use, remained drawn up on the threshold of the tower.

The donjon of Coucy is built in three stages, and has a large apartment, originally vaulted, on each floor. There is no basement chamber below the level of the entrance. In order to facilitate vaulting the various floors, each chamber was planned with twelve sides, lofty niches being left between the abutments of the vault.[211] Without giving a detailed description, we may notice the points in which this great structure resembles and improves upon the tower of Conisbrough. (1) The isolation of the tower, defended by its own ditch and, towards the field, by its own curtain, makes an entrance on the ground floor possible. In this respect, the builders of Coucy followed the example of Philip Augustus at the Louvre and at Rouen. (2) The defences of the entrance are more elaborate than at Conisbrough, where the doorway was closed merely by a strong wooden door, reinforced by two draw-bars, and a straight passage led into the guard-room on the first floor. At Coucy there was a similar door, but in front of it was an iron portcullis, worked from the first floor of the tower, and sliding through grooves at the back of the jambs of the doorway. The portcullis was defended further by a machicolation or open groove in the floor above. The entrance passage behind the wooden door was closed by a hinged grille at the entrance to the guard-room. (3) The stair, as at Conisbrough, was on the right of the entrance passage, but, instead of following the curve of the wall, was a vice, which led straight to the roof, communicating with the two upper floors on the way. The device adopted at Conisbrough, by which the stair ends at each floor, and, in order to ascend further, the floor has to be crossed, was adopted in the lesser towers at Coucy,[212] but not in the donjon. The Conisbrough method has the advantage, very desirable in a tower, of keeping the approach to the roof under direct observation throughout its entire distance: we find it used in the stairs of the rectangular keep at Richmond. (4) The tower of Coucy, as already noticed, was defended by a lofty parapet, pierced with arches, which, in time of siege, gave access to an outer wooden gallery supported by stone corbels.[213] The form of the corbels is that which became general in later times: each is composed of four courses of stone projecting one above the other, with their outer ends rounded. (5) The well at Coucy was in one of the niches between the abutments of the ground-floor vault. (6) There are garde-robes at Coucy on the left of the entrance-passage, and in a similar position at the entry to the first floor. (7) We have seen that at Conisbrough arms were probably transported from the basement to the roof through a series of trap-doors in the floors. At Coucy there was a circular opening left for this purpose in the crown of the vault of each floor. (8) The solidity of the tower of Coucy is emphasised by the absence of large windows, even more noticeable than at Conisbrough; and, although the tower contains fireplaces, its purely defensive character is unmistakable. It provided accommodation for an enormous garrison, but for residential purposes, it would have been uncomfortable to the last degree. It contains no trace of a permanent chapel: when the tower was in use, an altar might have been set up in one of the niches on the first floor; but the regular chapel was in the inner ward, and was connected with the domestic buildings.

In the walls of the tower of Coucy can still be seen the holes which served to attach the scaffolding during construction. The spiral course which they take shows that the scaffolding, rising with the tower, formed an inclined plane of a moderate slope, up which the necessary materials could be wheeled. The advantage of a cylindrical tower from this point of view is obvious. Another structural feature is the provision of gutters for the drainage of the roof in the stonework at the back of the vault-ribs of the second floor. The absence of any effective provision for draining the centre of the roof at Conisbrough points to the probability that it was sheltered, as already explained, by a conical roof of its own.

Pembroke

The introduction of the cylindrical donjon in England coincides with a period at which the keep was already beginning to disappear from the castle. The principal examples, which may be attributed to the early years of the thirteenth century, are on the frontier and in the south of Wales. Chief among them is the fine tower of Pembroke ([180]), which was probably built by William Marshal, earl of Pembroke and Striguil, about 1200. The castle of Pembroke was of great importance, owing to its situation upon an arm of Milford haven,[214] and its command of the passage to Ireland. The keep was probably the first completed portion of the present castle, the stone-work of which, as it stands to-day, is very largely of the late twelfth and early thirteenth century.[215] It is a round tower, with a basement and three upper floors, standing just within, but not touching, the curtain which divided the inner and higher from the outer ward. The height is 75 feet; the floors were of wood, but the uppermost stage was vaulted by a dome, which still remains, rising in the centre of the tower above the rampart-walk. The stair is a vice in the west wall, from the basement to the summit: the main entrance was upon the first floor, but there is also a basement entrance, which seems to have been pierced not long after the building of the tower. The whole structure batters upwards, and the walls are slightly gathered in at each stage on the outside, a method the reverse of that pursued at Conisbrough: the masonry is roughly coursed rubble. On each of the first and second floors there is, towards the inner ward, a two-light window with pointed openings, the spandrils between which and the enclosing arch are pierced with plate tracery. The third floor was lighted by windows pierced in the dome.[216] Commanding, as it does, the whole interior of the castle, this tower is remarkably grand in situation; and its thick walls offered considerable resistance to artillery. It shows, however, no advance upon the defence of Conisbrough. The rampart-walk is narrow, and the dome in the centre prevented the employment of the roof as a platform.

Pembroke; Plan

The cylindrical donjon in England and Wales was simply an experiment attempted here and there, as an improvement upon the rectangular tower, but was never carried to the general perfection which it attained in France. Its isolation at Coucy, upon the outer face of the inner ward, protected by its own inner ditch, and covered by a strong curtain of its own, are signs of a perfection of engineering skill to which our builders did not attain. In one case, at Flint, we find a round tower which is isolated within its own ditch at one corner of the castle, but stands outside the main wall, and had no separate curtain of its own.[217] The plan strongly suggests a mount-and-bailey fortress, the isolated tower occupying the site of the mount, and the bailey walled in, leaving the moat, which was marshy and was filled with water at high tide, clear. The construction of this keep is peculiar: it is composed of an outer and inner circle of masonry, with barrel-vaulted passages between the two. Its actual date is unknown.[218] But, as a rule, where the keep stands upon the outer line of defence, it is joined by the curtain of the bailey. Thus at Caldicot, near Chepstow, the castle is simply a mount-and-bailey enclosure surrounded by a stone curtain of the thirteenth century. The keep is a round tower at one corner, standing upon the partially levelled mount; and the curtain crosses the ditch to join it on both sides. At Conisbrough, where the keep was on the line of the curtain; at Pembroke, where it stood just within the line, there was no ditch round it: the high ground on which it was placed seems to have been thought a sufficient protection.