CHAPTER XII.
OF THE EDWARDIAN OR CONCENTRIC CASTLES.
EVERY castle, if more than a solitary tower or peel, and having more than a single line of defence, has more or less of a concentric character, but in most, even of the largest of the earlier castles, the secondary defences were of small extent and confined to works for the protection of the entrance, as at Richmond and Coningsborough, and such cannot, with any propriety, be called in a general sense concentric. At Richmond, for example, the original castle was an enclosure within a fortified wall of which the keep formed a part, a small barbican covering the entrance, and so of the purely Norman part of Corfe, of Coningsborough, of Brough, of Bridgnorth, and probably of the original Tower of London. None of these were originally concentric, nor can the term be correctly applied to the original castles of the early part of the reign of Henry III., nor even to some of those built by his son. White Castle, Grosmount, Cilgerran, and even Caernarvon and Conway, are mere enclosures, strengthened and fortified by mural towers and gatehouses upon a single line of wall. Salisbury was concentric by necessity, the earthworks leaving the builders no choice in the matter. The concentric arrangement has been supposed to have been introduced by Prince Edward from Syria. That so able a soldier, and so shrewd an observer, added to his knowledge of the military art by what he saw in Palestine is probable enough, but the system of defence for which his reign became celebrated was in truth introduced into England before the death of Henry and before Edward returned from the East. Caerphilly, one of the most complete examples of the concentric lines of defence, was constructed just before Henry’s death, and was the work, not of the sovereign but of a subject. Nevertheless, so great was Edward’s fame, that the system which, though he did not invent, he adopted, has been designated by his name, and the term Edwardian has been applied to that style of fortress, that took the place both of the round tower and of the walled enclosure, and carried forward the art of fortification from the Early English to the Decorated period of English architecture.
Edward’s policy, on his return from the East, and accession to the throne, led him not to build, but to pull down castles. In the fourth year of his reign it was enacted: “It is to be enquired of castelles, and also of other buyldings girt with dytches, that the walls, tymber, stone, lead, and other manner of coverynges are worth, and how they may be solde, after the very value of the same walles and buyldinges. And how moche the buyldinges without the dych may be sold for, and what they may be worth, with the gardens, custylages, dove house, and all other issues of the court by the yere.” Probably this mainly related to such unlicensed castles as had escaped the hands of Henry, as none of the older or more important structures were then pulled down. Many of these, indeed, had recently been augmented and embellished, and where it suited his convenience, Edward followed in the same track, strengthening and repairing decayed walls and towers, and adapting them to the changed circumstances of the time. Thus, at Porchester, he rebuilt the inner ward, and much enlarged the contained buildings. The additions to Middleham, an outer ward and gatehouse, are of his reign, and the vast outworks beyond the lake at Kenilworth, and the effect of these and similar alterations was to convert the original castles into those of the concentric type.
But it was in North Wales that circumstances called forth Edward’s talent as a military engineer. In that country the strong places were hill camps, unfitted for modern warfare, and out of the line of his operations. He found there neither English mounds nor Norman keeps, and his works are not only on a grand scale, but they are original. To him are entirely due the castles of Conway and Caernarvon, Beaumaris and Harlech. Possibly Bere Castle and Dolbadarn Tower were strengthened by him, but they rather resemble the early works of his father. In Scotland Edward’s works have been mostly destroyed, but his hand may be recognised at Linlithgow, possibly in the castle at Edinburgh, and in the old fortifications of Berwick.
The first characteristic of a concentric castle is the arrangement of its lines of defence, one within the other, two or even three deep, with towers at the angles and along the walls, so planned that no part is left entirely to its own defences. A wall cannot be advantageously defended unless so arranged that the exterior base of one part can be seen and commanded from the summit of another. A Norman keep or an Early English round tower could only be defended by the projection of missiles from the battlements, exposing those who discharged almost as much as those who received them. The employment of mural towers not only added to the passive strength of the wall whence they projected, but when placed within a bowshot distance enabled the defenders, themselves protected, to enfilade the intermediate curtain. By this means the curtain wall, that part of the work least able to withstand the strokes of the ram, became that in defence of which most projectiles could be brought to bear, whilst the towers, which from their distance apart were but imperfectly flanked, were from their form and solidity in little danger of being breached. By this means also material was economised. The walls were less thick, and the defence generally was carried on with more skill and less dependence upon passive strength. In this indeed there was nothing new, but not the less the principle was ignored in the construction both of keep-towers and their successors, the round towers, donjons, or juliets. But in the concentric system a good deal more than this was effected. The parts of the lines of defence were so arranged that the garrison could sally from one part, and so harass the attack upon another. Moreover each part, tower or gatehouse, and sometimes each stage of a building, was so contrived that it could be held separately for a short time. Also, from the concentric arrangement of the lines, a breach of the outer wall did not involve the loss of the place. The second ward, as at Beaumaris, Harlech, Caerphilly, or the Tower, was so narrow that in the event of its being entered from a breach, the assailants were exposed to an attack on either flank, in such a manner that their greater number could not be brought to bear, nor was there room to work a catapult or set up a malvoisin. In these castles, the keep, the main feature in a Norman or an Early English fortress, was dispensed with; it was developed, to speak anatomically, into an open court, strengthened at its sides and angles by gatehouses and mural towers, and having the hall and domestic apartments ranged against the wall along one or two sides. Around this inner ward was disposed a second ward, of narrow breadth, and broken up by cross walls. Sometimes around this second ward was disposed a third or outer ward, usually of large area, so as to accommodate the greater part of the garrison, the horses, and the neighbouring peasants with their cattle. In many castles this outer ward contained a ditch, or even a large sheet of water, as at Ledes, Caerphilly, and Kenilworth, formed by damming back a local streamlet. In such cases the defence of the dam became a matter of prime consequence, and was specially provided for by stout walls along its length, and towers or gatehouses at either end. In these castles every part is intended for everyday use. No part is set apart only to be inhabited during a siege. The hall, chapel, and kitchen were habitually used, and constructed on a fitting scale.
As Caerphilly is both the earliest and the most complete example in Britain of a concentric castle, it will be convenient briefly to point out its principal features. The position was selected to close a pass by which the Welsh were wont to issue from the hill country of Glamorgan into Monmouthshire, the way by the sea coast being barred by Cardiff and the castles of the vale. The spot selected lay between the Taff and the Rhymny, upon a gravel bank rising in a low marshy bottom, having mountainous, or at least very high ground to its north, south, and west. The central part of the bank was occupied by a rectangular enclosure, 70 yards by 53 yards, having at each angle a lofty drum tower, and in the centre of each end a broad and lofty gatehouse. On one side of this inner ward was the hall, 72 feet long by 33 feet wide, placed between the chapel and the private apartments, while the gatehouses also contained apartments second only to the hall in magnitude. This inner ward stood within a second and rather larger area, also rectangular, and 106 yards by 90 yards. This middle ward was provided with smaller gatehouses connected with those within, and was contained within a revetment and parapetted wall which descended 20 feet all round into water. Four parapetted bastions, corresponding to the interior towers, capped the four angles, and the side next the hall contained the kitchen and offices, and a water-gate opening from the hall by a broad passage with space for the stowage of boats.
The water by which these two wards were encompassed was on one side a deep and broad lake covering about 16 acres, and on the other side a smaller sheet of water of about 3½ acres. These two waters were connected by cross cuts at each end, traversed, opposite the gatehouses, by drawbridges. One of these dropped upon a tête du pont, a sort of hornwork or ravelin of earth, about an acre and a-half in area, and enclosed within a revetment wall duly parapetted, and probably with a stout palisade on the raised ground within. A branch from the lake encircled this work, and a second drawbridge connected it with the ground outside. At the opposite end of the castle another bridge dropped from the middle ward upon the outer ward, a very remarkable work. This was a raised platform nearly 330 yards long by from 14 yards to 36 yards in depth, covering the whole front of the castle, including the two sheets of water. The platform was divided near its centre by a lofty wall embattled on each face, and having a ditch along one of them. On this wall was a strong gatehouse having below a portcullised doorway, with a drawbridge connecting the two parts of the platform, and above, a smaller doorway, also protected by a bridge and portcullis, and guarding the way to the battlements of the outer wall. At one end of the platform was a postern connected with the stables, and at the other a cluster of towers on the outer bank of the lake, containing another postern. In the centre was the great exterior gatehouse, from the gateway of which a bridge dropped upon an enormous pier standing in the middle of the outer ditch, from the exterior face of which a second bridge dropped upon the village street. On the platform was a large corn-mill, and connected with it the dam and sluice by which the waters of the lake were retained and regulated, and which was very strongly fortified. Thus there were two great gates and two posterns at points of the castle distinct from each other, whence large bodies of cavalry could issue, so that the camp of a besieging force could be attacked from four directions, and, in case of failure, the castle could be reached by four entrances, besides two water-gates. In addition to these strategical arrangements, each tower and gatehouse had a portcullised entrance on the ground floor, and in the upper stories the lateral doorways opening on the battlements of the curtains were protected in a similar manner.
In a military point of view, Caerphilly is a work of consummate skill. Unfortunately for its historic fame, the settlement of Wales followed so closely upon its erection that it never attained to any great importance.
Harlech is a concentric castle, probably designed by the architect of Caerphilly. Here also is an inner rectangular ward, with drum towers at the angles and the hall, and other buildings on two sides. This stands within an outer ward, also rectangular, with parapetted walls and bastions. The inner ward has a large single gatehouse, connected with a second and smaller one in the outer ward, from which a drawbridge spanned a deep and broad ditch quarried in the rock. Harlech stands well, and occupies a bold headland of rock which formerly rose out of the sea, from which it is now separated by a broad tract of low land. Its great peculiarity is a covered staircase cut in the rock, defended seaward by a looped parapet, and closed above and below by small gatehouses. This was the water-gate of the fortress, and opened upon a small quay now occupied by the railway.