It is much to be regretted that so few of these shell keeps remain, even in ruin, and very few, indeed, in a state at all approaching to their original condition, for, as the representatives of a very early form of fortification, and as the chief seats of very ancient estates, and of original English families, they possess a very peculiar interest. Nor are they, when of large size, at all wanting in a noble effect. It is true that upon level ground, as that occupied by the Tower of London, or upon such a ridge as Corfe, or such an elevated platform as Hedingham, the rectangular keep produces a very fine effect, but there are positions in which this is fully equalled by the keeps of the other type. At Durham, where the central tower of the cathedral is equal in grandeur and simplicity to a rectangular keep, it is eclipsed by the adjacent castle. The keep of Belvoir, which, though rebuilt and weak in its details, retains its original outline, would be ill exchanged for the towers even of Norham or Lancaster, and no other structure could be substituted to advantage for the keep of Windsor, crowning and completing its “tiara of proud towers.” Massive as is the rectangular keep, simple, uncompromising, and warlike its features, still, even when seen to its greatest advantage, as on the promontory of Dover or the bold impregnable rock of Bamburgh, it must be confessed to be inferior in grandeur and in completeness of outline to the stern round tower of other days, identified as it is with the early residences of the adventurous Northmen who laid the foundations of the English people.

LIST (APPROXIMATIVE) OF SHELL KEEPS, PAST OR PRESENT.

Thus, of 119 presumed sites of shell keeps, there are set down 31 the evidence for which is imperfect, and 88 for the existence of which there is good evidence, and of these about 40 actually remain in a more or less perfect, or rather, imperfect, condition.

CHAPTER XI.

CASTLES OF THE EARLY ENGLISH PERIOD.

THE transition from the Norman to the Early English style, which in ecclesiastical architecture constitutes a period of great interest, is by no means, at least in England, so strongly marked in buildings of the military type. The rectangular and circular or polygonal keeps, with their Norman features, retained their hold upon English castle-builders through the reigns of Stephen and that of Henry II., 1135–1189, or for a century and a quarter from the Conquest, or even later. At Dover, the dog-tooth ornament and a bead moulding, combined with very decidedly Norman features, mark the Transition period, as do the ornamental details of the rectangular keep of Helmsley, and the particulars of the shell-keeps of Tamworth and York. The later keeps are known by the increased depth of the pilasters, which become buttresses, as at Dover and Clun, and in the twelfth-century keep of Chambois (Orne); sometimes by their improved and fine-jointed ashlar, as at Hedingham; by a more frequent use of the stone of the district instead of that brought from Caen; by the presence of ribs upon the groins of the hip-vaulting of the galleries and mural chambers; by the use of nook-shafts at the exterior angles, as at Scarborough and Castle-Rising; and by the greater tendency to ornament about the rib bosses, door cases, window recesses, and fireplaces; and by the more or less Early English character of such ornamentation. The portcullis is perhaps less rare in the later keeps. There was, however, little change in the internal arrangement so long as the Norman outline was retained, and but little tendency, so far as the keep was concerned, towards flanking defences. Passive strength is still relied upon.

Little is known of the castra adulterina, of which so many score were constructed during the reign of Stephen, and destroyed by his successor. They could scarcely be of the solidity of the Norman keeps, else their demolition would have been a more difficult task. They were probably either of timber, or mere walled enclosures of no great strength. Few, if any of them, represented the chief seats of large estates, and being built for the most part on new sites, the earthworks were inconsiderable, and where the works above ground were destroyed there was little left to show where was their site. Among the latest rectangular keeps should be mentioned the tower at Penhow, Monmouthshire, the cradle of the house of Seymour; and that of Fonmon, in Glamorgan, still inhabited. They are small, without pilasters, and with scarcely any Norman features, and belong to the Early English period, as, judging from its foundation laid open and from some fragments dug up several years ago, did the castle of Sully, near Cardiff, and probably that of Dunraven, in the same county, the remains of which are built into a later house.

By degrees, as the Norman towers and shell-keeps fell out of fashion, they were succeeded by towers of a cylindrical form, known as Donjons or Juliets, and this change corresponds to the middle period of the Early English style in ecclesiastical architecture. Scientifically, in a military point of view, this was scarcely an advance, for the defenders of an isolated round tower could not concentrate their fire, and could only protect the foot of the wall by exposing themselves at its summit. On the other hand, with equal material, the round tower was stronger, and more difficult to breach or to bring down by a mine. Also, it admitted of being vaulted in every story, and was thus more solid and less exposed than the rectangular keep to being set on fire, either from within or by balls projected upon its conical roof. Usually, however, in England, only the basement was vaulted, as at Brunless. At Pembroke, the great round tower is vaulted at its summit, as are some of the cylindrical towers in the enceinte; but it is possible that these elevated vaults may be additions. At Coningsborough the basement alone is vaulted, and the vault is entered by a ladder from an aperture in the centre of the dome, under which is the well; the basement, as in Norman and Early English towers generally, being used as a store-chamber, and seldom, if ever, as a prison. In fact, in a single tower, whether rectangular or cylindrical, intended by its passive strength to defy attacks and to wear out the patience of a blockading force, an ample store of provisions was of the first consequence, and to their storage all the spare space was necessarily devoted. In those days, when the keep was the citadel, and not unfrequently used as such, prisoners were not kept within its walls. Dungeons there were none, save in a very few exceptional cases, and the basement or ground-floor was invariably occupied as a magazine.