CHAPTER IX

CASTLES OF THE THIRTEENTH CENTURY: THE FORTIFICATION OF THE CURTAIN

The keep had a traditional importance in the scheme of the castle, and the main energy of the castle-builders of the twelfth century was directed towards strengthening its power of resistance. But the improvement of siege artillery naturally turned their attention to the strengthening of the outer defences as well. The day of the palisade was past, and the stone curtain called for more scientific treatment than it had yet received. In the thirteenth century, then, military engineers began to concentrate their ingenuity upon the outer walls and entrances of the castle. Their interest was transferred by degrees from the keep to the curtain, while, at the same time, the domestic employment of the keep ceased in favour of the more comfortable quarters against the castle wall. In this way, as scientific fortification developed, the keep dropped into a secondary position, or was left out of the plan altogether.

In tracing this gradual disappearance of the keep, it should be kept in mind that the stone keep, when we first meet with it, is actually a supplement of more permanent material added to a palisaded enclosure. In early walled enclosures, like Richmond or Ludlow, the stone defences made the special provision of a keep unnecessary: the whole castle, protected by its stone wall, had in itself the strength of a keep. It was only when it became likely that the stone curtain might show less resistance than its builders anticipated, that, in both the castles just mentioned, a tower-keep was provided. In both cases, the tower stood in the forefront of the defence of the principal ward of the castle. In the first instance it protected the curtain, while, if all else failed, its use, the primary use of such buildings, as an ultimate place of retirement for the defenders, could be demonstrated. During the reign of Henry II., the stone keep, whether a tower or a shell on the mound, was the dominating feature of the stone-walled castle. At Conisbrough and Pembroke (181) the great tower still keeps its pride of place, but the curtains of the ward in which it stands have been built or reconstructed with a view to effectual flanking; while the two semicircular towers which guarded the southern curtain of the inner ward at Pembroke were evidently an addition, after the keep had been built. In castles like Manorbier, the oldest parts of which are of the later part of the twelfth century, the builders returned to the original keepless plan of Richmond and Ludlow. The care, which, in the earlier castles, had been expended upon a single rallying point in the scheme of defence, was now applied to the whole outer wall of the castle, so that it began to offer a connected front to an attack.

During the transition, however, the keep, as we have seen, received its full share of attention. At Château-Gaillard (163) it was an integral part of one united design, the outer defences of which remain to be described. The great tower is at the highest point of the inner or third ward, which forms an irregular oval. But, before reaching this ward, two outer lines of defence had to be forced. There was only one possible approach for a besieging army, along the isthmus on the south-east side of the cliff. On this side the castle proper was protected by a powerful outwork, which offered a sharp angle to the isthmus. When Philip Augustus began to use his machines against the castle in February 1203-4, the round tower at the apex of this horn-work[242] was the main object of his attack. The sloping sides of the angle were flanked by two smaller round towers, while the entrance, close to the north angle, was covered on one side by a cylindrical tower, to which there was probably a corresponding tower in the opposite curtain. The horn-work was surrounded by an outer ditch. The strength of the curtain seems to have been little affected by the siege-engines. Breaches, both here and in the inner ward, were not made until Philip’s miners had weakened the masonry by boring galleries beneath it. A very deep ditch with perpendicular sides, cut in the chalk, stretched across the whole ridge, and divided the outwork from the middle ward, which was capped at the angles by cylindrical towers, and contained buildings of which the substructures, and some cellars excavated in the chalk, are left. The curtain of this ward was continued along the face of the precipice and the north-eastern slope, so as practically to enclose the inner ward. The two wards, however, were not concentric, for the inner ward occupied one end of the space enclosed by the middle ward, from which it was divided by a ditch. The wall of the inner ward was the most remarkable and original of the defences of the castle. Its whole outer face, save on the side next the precipice, was formed of a series of convex curves intersecting with each other, so that no flat surface was left. The wall is solid, and, looking at its fluted outer surface, we may well admire Philip’s military skill, which found it a not too formidable obstacle. A gateway in the east face gave access to the inner ward from the narrowest portion of the middle ward, and the ditch at this point was originally crossed by a stone causeway. The projecting spur of the great tower faced the gateway. The whole formidable design was perfect from the point of view of flanking, while the plan was a step towards the concentric arrangement of one ward within another. The prominence of the keep in the plan was, however, an archaic feature; and the history of the siege of 1204 shows very clearly that the great tower was practically a superfluity, and that the last hopes of the defenders were centred in the wall of the inner ward. When Philip’s miners had endangered its stability, and his engines were brought to play upon the weakened stonework, their hope was lost.[243]

The inventive skill shown in the inner wall of Château-Gaillard was not displayed again in the same form. But a step in the flanking of the curtain by round towers is seen in the wall of Conisbrough (217). Here the inner ward is nearly oval, and the southern half of the curtain, in which is contained the entrance from the outworks, is strengthened by small solid towers with battering bases, projecting some two-thirds of a circle from the wall.[244] Such solid projections for flanking purposes are found at Scarborough and Knaresborough, and could be easily added to an earlier wall, when necessity required. For the convenience of the defenders, however, larger towers with rooms on each floor were desirable; and the actual improvement of the defences of the curtain is seen in the multiplication of such towers, so as to leave no part of the wall unflanked. The circular or polygonal form was almost universally adopted for them.

Warkworth (49) is an example of a twelfth-century castle in which an approach was made to an adequately defended curtain, although with long distances between the towers. The arrangement, however, is a complete contrast to the haphazard projection of towers from earlier curtains, as at Ludlow. The castle stands high on the right bank of the Coquet: the river bends round it, so that the only level approach is from the plateau on the west side, and the town climbs the tongue of land between the castle and the river.[245] The mount is at the apex of the castle site, immediately above the town. On the west side of the enclosure the curtain, which is strong and thick, is unbroken by any tower: against the inner face are the domestic buildings. The south wall, which contains the gatehouse, is flanked by two angle-towers, on the west by the tower known as “Cradyfargus,” and on the east by a square tower, called the Amble tower. In the east wall, which commanded the ascent from the town, is a half-octagon tower, in each face of which is a huge loop for a cross-bow, so that a few archers could effectually rake the path outside with their fire. Of these towers, Cradyfargus projects into the castle enclosure with a blunt angle, its walls on this side being a mere continuation of the curtain. The basement was entered from the cellar behind the hall, the first floor from the great chamber above, and the second floor by a stair in the thickness of the wall from the vestibule or landing, west of the great chamber. The projection of the eastern tower is entirely outward: its internal face was flat. There was a basement and two floors: the first floor had an external stair from the ward, but it does not appear how the second floor was reached, though the jamb of a door may still be seen. The east tower had a garde-robe near the entrance of the basement and on the first floor: in Cradyfargus there are only traces of garde-robe arrangements. Although the space enclosed by the walls was large, and the flanking by no means perfect, the two most assailable sides of the fortress were very secure. The gatehouse, a building of about the year 1200 (221), formed an intermediate projection in the south wall between Cradyfargus and the Amble tower: the gateway is recessed between two half-octagon turrets. The preference of polygonal forms for the defences of this castle is rather characteristic of the north of England. There was, however, a conservative spirit in this district, which is seen in the retention of the rectangular form for the Amble tower. Even in a fourteenth-century castle like Dunstanburgh the angle towers are rectangular in form; while the “pele-tower” of the northern borders, throughout the middle ages, shows no important variation from the square form.

The importance given to the gatehouse at Warkworth was a sign of the times. We have seen how, at Lewes and Tickhill, the first thought of the builders was to provide their earthworks with a stone house of entry. Norman gatehouses were very simple in construction. The gatehouse at Warkworth, on the other hand, was anything but simple in its arrangements, and all the forethought possible was taken for its defence. There are three stories, the lowest of which is the vaulted hall of entrance to the castle, flanked, in the ground-floor of the half-octagon towers, by guard-rooms described in the survey of 1567 as a porter’s lodge and a prison. The defences of the passage need close attention. The entrance was closed by a gate which opened outwards, and stood about 4 feet in advance of the portcullis: the space between was commanded by arrow-loops in the walls of the guardrooms. The herse of the portcullis seems to have been worked from the second floor of the gatehouse:[246] the upper and broader portion ran in a groove which ceases at the level of the string-course below the vault of the passage, while the lower descended to the ground. Beyond the portcullis, the passage was kept under observation through cross-loops in the side walls. The vault stopped 5 feet short of the inner gateway, and the passage was covered by a wooden roof. On each side of the inner gateway were the entrances to the guard-rooms, which flanked the whole passage.

The plan of the castle gatehouse at Warkworth was that of the great majority of medieval gatehouses, whether in castles or in the walls of fortified towns. The ground-floor of the main block of building, which generally had two upper floors, contained the hall of entry, and was flanked by two cylindrical or octagonal towers, the lowest stories of which were guard-rooms, and were pierced with loops commanding the approach and the passage. Usually the gateway was placed at the back of an arched recess, which formed a porch. The position of the gate and portcullis at Warkworth was rather exceptional. Ordinarily the portcullis descended in front of the gate, which opened inwards, and was secured, when closed, by one or more draw-bars. This, however, was impossible, where the gate, as at Warkworth, opened outwards, so that the usual arrangement had to be reversed. But, while the actual plan of the gatehouse kept its general characteristics with little change, the defences of the entrance were multiplied. Thus the Byward tower, the outer gatehouse of the Tower of London, had an outer portcullis in front of a wooden door opening inwards, behind which was a second portcullis, blocking the entrance to the inner and wider portion of the passage, which had a timber ceiling. In addition to this, between the outer portcullis and the gate, the vault was crossed by a rib, pierced with three holes, which allowed the defenders to harass an attacking party from above, and also could be used for strengthening the gate in time of siege by a timber framework, the upper ends of which were fixed in the holes. Such holes, which were not merely machicolations in the vault, are found elsewhere, as in the gatehouses of Pembroke and Warwick castles and the west gatehouse of the town of Southampton. In this last case, a single rectangular gate-tower projected from the inner face of the wall only, next the town. The gate of the passage through the ground floor was defended upon its outer face by these holes alone: there were two portcullises, but both were upon the inner side of the gate. It is possible that such holes were originally left to fix the centering of the vault when it was first built: they converge towards one another, and probably were not filled up afterwards, in view of their defensive use.[247]

One prominent feature, however, of the defences of a gateway, as time went on, was the provision of machicolations, in the shape of long rectangular slits, in the vault of the passage and in the arch in front of the portcullis. In some cases where they occur in connection with a portcullis, they may have been used for a heavy wooden frame, which could on occasion reinforce the iron herse of the portcullis. At Warkworth there is no original arrangement of this kind: the wall of the first floor above the gateway projects slightly upon a row of corbels, but this was done merely to give it additional strength. At a later date, however, the parapet at the top of the gatehouse was corbelled out, and the spaces between the corbels left open for machicolations. From the later part of the thirteenth century onwards, the usual arrangement, as at Chepstow or Tutbury, was to carry the parapet upon an arch in advance of the main face of the gatehouse, from one tower to the other, and to leave the space between the parapet and the main wall open, so that it commanded the field immediately in front of the portcullis. The effect of recessing the front of the gatehouse within a tall outer archway is magnificent, from the point of view of design. The design of gatehouses reaches its highest point in the great gatehouse of Denbigh, with its octagonal gate-hall, and in the King’s gateway at Carnarvon, where the enclosing arch, recessing the two lower stages of the gatehouse, bears the outer wall of the upper floor (253).

In some instances, as at Pembroke (224) and Kidwelly (225), where the gatehouse passage was defended by inner and outer portcullises, there are as many as three chases or slots in the vault between the outer and inner entrances. At Pembroke, where the gatehouse has the unusual feature of two flanking towers (213), of semicircular projection, on the side next the ward, an arch was thrown out from one tower to the other, some distance in advance of the inner archway. It is difficult to see how this inner barbican, as it may be called, was intended to be of use to an already strongly protected gateway; but the space within it may have been covered by a wooden platform, accessible from the first floor of the gatehouse, from which the interior of the castle could be commanded, and an enemy who had forced an entrance could be seriously annoyed. The vault of the entrance passage was generally a pointed barrel-vault, strengthened by transverse ribs at intervals; but the broader space in the centre of the passage was often ceiled, as in the Byward tower, with timber. The entrance passages of the inner gatehouses of Harlech (274) and Beaumaris (236) were roofed with wooden ceilings, supported by transverse ribs of stone set with only a narrow interval between them.

The ground-floors of the flanking towers of the gatehouse were usually vaulted. The lodges from which the towers were entered, upon each side of the inner passage, had stone ceilings when the passage itself was vaulted through its whole length, or when they formed one room with the ground-floors of the towers. The ordinary plan, however, was to treat the flanking tower as an outer guard-room, approached from the inner lodge. If it was cylindrical in plan, the interior was arranged as a polygon, and vaulted with ribs springing from shafts in the angles.[248] This plan may be seen in the Byward tower and Middle tower of the Tower of London. In both towers the inner part of the passage was ceiled with timber, and the adjacent chambers formed lobbies to the vaulted ground-floors of the towers. In the Middle tower, however, the left-hand lobby was occupied by a vice leading to the first floor; and in the same position in the Byward tower is a square rectangular chamber with a ribbed vault.

A good normal gatehouse, which may be taken as typical of the period, is that of Rockingham castle (226). Its details indicate that it belongs to the later part of the reign of Henry III. It is upon the east side of the enclosure, and its projection is almost entirely towards the field. The plan is, as usual, a rectangle with a passage through the centre, and with semicylindrical towers projecting on either side of the outer entrance. No vaulting was used. The passage is entered through a porch beneath a drop arch—that is to say, a pointed arch whose two segments are drawn from centres below the springing line—and was guarded, just within the arch, by a portcullis in front of a wooden door. At the inner end of the passage was another door. Openings in the side walls of the passage communicated with rectangular chambers;[249] and in the east walls of these were doorways into semicircular chambers within the towers. There was only one upper floor to the gatehouse and its towers. In this simple building, one is reminded at once of the rectangular stone gatehouse of the early Norman castle, with its upper chamber. Improvement is seen in the substitution, for the original entrance, of a central passage flanked by chambers upon the ground-floor; in the addition of flanking towers of scientific form; and in the protection of the timber doors by an iron portcullis.

The gatehouse at Newcastle, known as the Black gate (227), which became the entrance to the castle in the thirteenth century, is an example of a more elaborately constructed and exceptional type. The ground plan is simplicity itself, a central passage flanked by towers containing guard-chambers. The towers, however, are not merely projections from a rectangular body, but flank the whole gateway with a wide convex curve. There is a large single vaulted chamber on the ground floor of each, lighted by loops which enabled the occupants to command the castle ditch. The architectural details of the gateway are very simple, but there is a short arcade of trefoiled arches in each of the side walls, and the vaulting of the guard-rooms presents some ingenious peculiarities. The upper portion of the gatehouse was much altered in the seventeenth century. The original design, with its great segmental flanking towers, may have been the prototype of the even more noble gatehouse of Dunstanburgh, which is a work of nearly three-quarters of a century later.[250]

The upper floors of the gatehouse may be reserved for discussion until we come to the concentric plan, in which the gatehouse became a building of exceptional importance. For military purposes the one necessary upper chamber was that in which the machinery controlling the portcullis was worked. In the floor of this room was the upper end of the groove, through which, by means of a pulley in the ceiling, the iron frame was drawn up or down, hanging here when it was not in use to close the entrance below. Many examples of a portcullis chamber remain, as at Berry Pomeroy and in Bootham bar at York.[251]

The entrance of the castle, under improved conditions of fortification, was defended by an outwork or barbican. The term “barbican,” which seems to be of eastern derivation, was used indiscriminately to denote any outwork by which the principal approach to a castle or a gateway of a town was covered. The word “barmkin,” which is possibly, as already noted, a corruption of “barbican,” was applied in the north of England to the outer yard of a “pele,” or fortified (literally, palisaded) residence. In many castles, as at Ludlow, Denbigh, or Manorbier, the outer ward was an addition or supplement to the plan of the castle, guarding the approach to the inner ward or castle proper, and its curtain was subsidiary to the strongly fortified curtain of the inner ward. Such outer wards or base-courts resemble the northern “barmkins,” an exact parallel to which is seen in the base-court of the fifteenth-century fortified house of Wingfield. Covering outworks were by no means uncommon, and also served the purpose of a barbican. As at Château-Gaillard, they might take the form of a walled outer ward, or, as at Llandovery, they might be horn-shaped earthworks, thrown out at an exposed point in the defences; in either case, they had their own ditch, an extension of the main ditch of the castle. But the barbican proper was a walled extension of a gatehouse to the field, confining the approach to the limited area of a narrow passage. The most simple instance is the barbican in front of Walmgate bar at York (229), where a gatehouse, originally of the twelfth century, was strengthened by the addition, upon the outer side, of two parallel walls at right angles to the sides of the gateway. Thus, in order to force the gates, an attacking party would have to traverse a long and narrow alley between high walls, in which they were exposed to the missiles of the defenders concentrated upon them from the ramparts of the gatehouse and the adjacent wall.

The barbican was, in fact, an application to the main entrance of the castle of the form of defence hitherto applied most scientifically to the fore-building of the keep.[252] Its general employment as an outer defence was the direct consequence of the removal of interest from the keep to the curtain. Not merely had the wall itself to offer a stout resistance to attack, so that every point was simultaneously engaged in active defence; but the main approaches had to be so arranged as to involve an enemy in perplexity. In the protection of the main avenues of access to the town or castle, we arrive at an unconscious reproduction in stone of the methods employed by prehistoric builders of earthwork. Experience taught the engineers of the thirteenth and fourteenth centuries the lessons which she had taught the makers of Maiden Castle, and the adoption of the concentric plan of fortification followed as a matter of course.

The contraction of the main entrance of the castle by a barbican is well seen at Bamburgh, Conisbrough (217), and Scarborough (129). In the first two instances, owing to the isolated position of the fortress, and the nature of the ground outside, the main approach would have to be in any case by a path made up the steep face of the hill, and immediately below the curtain. Bamburgh was unusually well aided by nature, and the gateway, flanked by two slender round towers, is at a level considerably lower than that of the summit of the rock; in this case, the rising road within the gateway, cut in the basalt, and commanded by the curtain and the keep within the curtain, was the barbican of the castle. The hill on which Conisbrough was set is merely a steep knoll, with a wide outer ditch on its less precipitous side. The outer ward, on the south-west side of the ditch, was apparently an earthwork without stone walls.[253] A gatehouse was set on the edge of the ditch, in advance of and at a lower level than the curtain of the inner ward. Its arrangements, so far as they can be traced, were not greatly superior to those of early stone gatehouses. Its lateral walls, however, were prolonged up the edge of the slope to the entrance of the inner ward. The left-hand wall joined an angle of the curtain half-way up the passage; the wall on the right hand was continued so as to cover the inner gateway, which was at right angles to the passage thus formed.[254] As at Bamburgh, the approach in this case is a narrow gangway between high walls, commanded throughout from the rampart of the inner ward, and, for the second half of the distance, passing immediately beneath it. A passage of this type, with a right-angled turn at its far end, might easily become a death-trap for a besieging force.

At Scarborough the castle cliff is almost entirely separated from the town by a deep ravine, and the approach is along the narrow ridge between this chasm and the northward face of the rock. The gatehouse, flanked by rounded towers, forms part of a small and irregularly shaped walled outwork or barbican placed upon the outer curve of the ravine. From this _tête-du-pont_, as it may be called, a straight passage, walled on both sides, crosses the head of the ravine, passing over a bridge on its way, and skirting, on the left hand, the sheer edge of the cliff. On the further side, the space widens into the outer ward, commanded and nearly blocked by the rectangular keep. The wall on the left is continued along the edge of the cliff, while that on the right, which, as being more open to attack, is much the thicker, bears away with the curve of the slope, and joins the south curtain of the inner ward upon its west face.[255]

The examples already given illustrate the precautions which thirteenth-century engineers took to guard their castles from surprise and storm; and the arrangements found in the Welsh castles of Edward I.’s reign are even more remarkable. It will be noticed that in the three castles just mentioned the main gatehouse is thrown forward to the outer end of the barbican, which forms a narrow passage uniting the gatehouse to the inner entrance. In late thirteenth and fourteenth century castles, however, the barbican was, as we see it at Walmgate bar in York, an addition to the front of a gatehouse. This method of covering gateways by outer defences is seen at Kenilworth, where the approach to the outer ward of the castle, across the lake formed by the damming-up of two rivulets, was broken up into sections by three lines of defence. First, an outer earthwork, segmental in shape, and strengthened by round stone bastions, guarded the approach to the first gatehouse. Beyond this gatehouse, which formed a _tête-du-pont_ like the Middle tower at London, a long causeway or dam, with a wall on its eastern face, crossed the lake to the strong gatehouse known as Mortimer’s tower, which, guarded by two portcullises, stood upon the end of the dam, in advance of the curtain. But the ordinary barbican, which was characteristic of the castles of the fourteenth and fifteenth centuries, was not a long and elaborately protected line of outer defences, but a stone building thrown out in front of a gatehouse, so as to concentrate the attacking force into a small space, and prevent a combined rush on the principal gateway. The contracted approach thus made was usually, in the later examples, as at Warwick (231), Alnwick (243), and Porchester, all barbicans of the fourteenth century, a straight lane between walls. At Porchester it is set in front of the twelfth-century gatehouse of the inner ward, which was covered in the early fourteenth century by a rectangular projection, pierced by lateral doorways opening upon the scarp of the inner ward outside the curtain. The barbican proper, somewhat later in date, is composed of two parallel walls, guarding the drawbridge from the base-court or outer ward. A loop cut obliquely through the west wall of this passage opened towards the west gateway of the base-court, so that a surprise of the barbican could be prevented. In this case, as at Alnwick, the approach to the barbican was a drawbridge; but at Alnwick, where the drawbridge crossed an outer loop of the castle ditch, the ditch proper was crossed by a second drawbridge within the barbican.

At Lewes, about the end of the thirteenth century, a barbican was added to the front of a Norman gatehouse which was of much the same character as the gatehouses at Porchester and Tickhill. The addition here took the shape of a short passage with a wall on each side, finished at its outer end by a new and lofty gatehouse, rising from the middle of the outer ditch of the castle, and approached by a mounting roadway. The shape of the new gatehouse is an oblong, with its main axis perpendicular to the road, but its angles were capped by round turrets, corbelled out at a point near the spring of the entrance archway (98). Such turrets are known as bartizans, and are common in French military architecture of the thirteenth and fourteenth centuries. They were not so usual in England, and are seldom found on such a scale as at Lewes: smaller bartizans, corbelled out at a point nearer the battlements of the building in which they occur, may be seen in the gatehouse at Lincoln, and at the angles of the towers of Belsay (313) and Chipchase in Northumberland.[256] The parapet of the barbican gatehouse at Lewes is brought forward from the wall on a row of corbels so as to allow room for six formidable machicolations. The work bears some resemblance to the _châtelet_ which covers the main entrance of the fortified abbey of Mont-Saint-Michel (235).[257] In France an outer gatehouse like that at Lewes, or an outer enclosure like that at Scarborough, bore the name of _châtelet_ or _bastille_. All such defences in advance of a gateway, whatever the special name they may bear, may be classed under the head of barbicans.

In the highest examples of military skill in fortification—at Conway (254) and Beaumaris (236), for instance—the greatest care was taken to cover the gateways with oblique or right-angled approaches, so that straight access should be impossible to an enemy. The same method of hampering the path of an enemy with right angled turns is noticeable in French examples of fortification, and notably in the gateways of Carcassonne (239). In England, however, an entrance defended by a barbican in a straight line with it was generally preferred; and, even in castles like Caerphilly and Harlech, the strength of the entrances depended upon the disposition of the concentric wards of the castle, and they were guiltless of the devices and traps which are one leading feature of Beaumaris. A good example of an oblique approach to a thirteenth-century castle is at Pembroke, where the main gateway is covered by an open barbican, forming a rectangular vestibule, the entrance to which is in a wall nearly at right angles to the gateway. The west gate of Tenby is covered by an almost semicircular barbican, the original entrance to which, with a groove for a portcullis, is on the north side, so that an angle had to be turned before the gateway was reached. At a much later date other openings were pierced in the outer wall of the barbican, and the curious arrangement is known to-day by the misleading name of the “Five Arches.” The east side of the chief ward of Carew castle was protected by a rectangular outer court, entered from the field by a small gatehouse. The gatehouse of the inner ward is in the south half of the east wall, and is flanked by a round angle-tower and a tower which projects from the middle of the wall. The outer faces of these two towers were joined by a wall which thus covered the gatehouse, and was pierced by a doorway, set a little to the north of the main entrance, with its jambs sloping to the left. This gave access to a walled-in passage, with an upper floor, leading obliquely to the inner entrance. As this side of the castle was on level ground and was much exposed, special care was taken to guard the approaches; there was, however, only one portcullis, at the inner end of the main gateway; but the wooden doors, four of which had to be passed before the portcullis was reached, were of great strength, and each was closed with several very massive draw-bars.

The town gateway at Tenby may be compared to the Porte de Laon at Coucy, which was also covered by a semicircular barbican. While, however, the Tenby barbican was directly attached to the wall, the barbican at Coucy was separated from the gateway by the town ditch and a bridge, and was altogether more elaborate. The bridge itself crossed the ditch in two sections, describing an obtuse angle, at the apex of which was a round tower. The road passed through the tower, and turned the angle at its inner gate, from which the second section of the bridge passed straight to the actual gateway. At Coucy all the resources of fortification were displayed; while at Tenby the application of the same principle was simple and unpretending.[258] Equally masterly is the oblique entrance to the castle of Kerak in Syria, beside which the entrances to Pembroke and Carew are of small account.[259] The long rectangular castle of Kerak is divided into two nearly equal wards by a wall parallel to its major axis. The main gateway is on the east side of the junction of the cross-wall with the outer curtain; but, instead of leading directly into the castle, the path turns to the left after passing through the gateway, and is confined within a long inner barbican, from the end of which a gatehouse at right angles gives admission to the interior of the upper ward.

The importance attached, from the thirteenth century onwards, to the gateway and its approaches, and the prominence of the gatehouse in the concentric castle of Edward I.’s reign will now be understood. It now remains to speak of the defences of the exposed face of curtain between the towers, and of the towers themselves. The progress towards effective flanking has been traced already, and the towered curtains at Dover (126) or the Tower of London are examples of scientific flanking achieved by long experiment. The towers rose above the level of the curtain, and were entered on the first floor from the rampart-walk, which they commanded. The walk, in fact, passed through the towers, as it may still be seen passing through the gatehouses at York. Thus each tower was the key to a section of wall; and, as the Crusaders found at Antioch, the wall could be taken only by the capture of several towers, each of which guarded a separate section.

The rampart-walk between the towers occupied, as from the earliest times, the top of the wall, and was defended by battlements upon the outer, and sometimes by a low rear-wall on the inner side.[260] The chief access to it was by stairs in the towers, but sometimes, as at Alnwick, there was a stair from the interior of the castle, built at right angles to the wall (241). In the shell-keep on the mount at Tamworth, there is a small stair which ascends in the thickness of the wall. The principal alterations which took place with regard to the rampart-walk were concerned with the treatment of the parapet. The division of the parapet into merlons or solid pieces by embrasures has been explained already, and it has been seen that, in the first instance, the embrasures are pierced at rather long intervals. The tendency grows, however, to multiply embrasures and narrow down the merlons between them, on the theory that the archer, discharging his arrow through the embrasure, can shelter himself and re-string his bow behind the merlon. The merlon, however, in works designed with a purpose mainly military, is usually broader than the embrasure, and is itself pierced with a small arrow-loop, splayed internally. This may be seen in the town-walls of Aigues-Mortes (77) and Carcassonne (78), where the merlons are of great breadth, and in such triumphs of fortification as the castles of Carnarvon (246) and Conway.[261] The merlons, however, were not always provided with loops, even in the Edwardian period. The barbican at Alnwick (243), a work of the early fourteenth century, is battlemented with plain merlons and embrasures. In this case, there are two further points which deserve notice. The embrasures at Alnwick were defended by wooden shutters, which hung from trunnions working in grooves in the adjacent merlons. The shutters could be lifted out at pleasure, and the embrasure left free: the device may be noticed in some other instances.[262] Also, upon the merlons at Alnwick stand stone figures of warriors, sometimes called “defenders,” and supposed to be designed to strike terror into the enemy. The present figures at Alnwick are comparatively modern; but the fashion was not uncommon and was purely ornamental. Similar figures are seen on the gatehouse of the neighbouring castle of Bothal, and upon the gatehouses of York: among the figures on the merlons at Carnarvon was an eagle, which gave its name to the famous Eagle tower. An enemy who could be daunted by the illusion of a rather diminutive archer or slinger balancing himself on a narrow coping, must have had very little experience of warfare. The merlons were treated very plainly in many French examples, as at Avignon, Aigues-Mortes, and Carcassonne (242), where they are flat-topped and unmoulded, while the embrasures have flat sills. In England they were generally finished off by a gabled coping, as at Carnarvon, where the top of each is moulded with a half-roll to the field (246).[263] The sill of the embrasure has also an inner chamfer. It may be noted that the freedom with which machicolations were employed in the parapets of French castles and town-walls was unusual in England. Machicolated parapets were, as a rule, confined to the fronts of gateways, until the later part of the fourteenth century, when they began, as at Lancaster and Warwick, to show themselves in the towers of the gateway and curtain. They are very sparingly used in the Welsh castles, which are our noblest examples of military architecture; and an _enceinte_, like the city wall of Avignon, in which the whole parapet is machicolated and built out on long corbels of considerable projection, is unknown in England.

What has just been said of the parapets of walls applies naturally to the parapets of towers. Towers on the curtain had, as we have seen, a double use. They flanked the wall, so that each pair could rake with their shot the entire face of the _enceinte_ contained between them. They also commanded the rampart-walk, so that an enemy who scaled the wall was still exposed to their fire and confined to a limited area. A distinction, however, must be drawn between the closed and open types of tower, as they may be called. The ordinary rampart tower was of two or three stages, divided into a basement and upper guard-room or rooms. The basement was sometimes vaulted, as in the northern tower at Pevensey (247) or towers at Alnwick. Fireplaces and garde-robe chambers are often found in the upper rooms,[264] the garde-robes being often placed at the junction of the tower with the curtain, and corbelled out over the outer wall.[265] At Carew, where there was no keep, but the castle formed a rectangular enclosure with drum-towers at the angles, all the towers were provided with garde-robe chambers, which, with the passages leading to them, are roofed by lozenge-shaped slabs, corbelled out one above another. In the south-east tower, the first-floor chamber has a pointed barrel-vault, and is entered by an outer stair from the ward. In the east wall are two garde-robe chambers, entered by elbow-shaped passages. Each had a door opening inwards, and was lighted by a separate loop. The chambers were so planned that the seats were placed on opposite sides of a partition wall, with a common vent.

The tower at Carew just mentioned is at earliest of late thirteenth-century date, and has several advanced features. Though its projection from the curtain is regularly rounded, its inward projection is rectangular, so that its plan is actually an oblong with a rounded end. It seems to have been intended to have been used in connection with the gatehouse: its first and second floors had no direct communication with each other, but both communicated with the gatehouse, and the ground-floor of the gatehouse had a large lateral opening in the direction of the first floor of the tower. The corresponding tower at the north-east angle was used in connection with the domestic buildings, and had a vaulted chapel (248) upon its first floor, from the north wall of which open two rooms for the use of the priest, with a garde-robe in the second. One tower, therefore, was purely defensive, additional precautions having been taken, no doubt, to guard a postern which opens from the basement upon the scarp of the ditch; while the other was merely an annexe to one of the two dwelling-houses within the enclosure. The use of the eastern and south-western towers at Warkworth (49) was equally distinct. We have seen that the south-west tower (Cradyfargus) was used in connection with the domestic buildings: this may not have been its original purpose, but it was certainly thus employed early in the fourteenth century. The great feature of the east tower is the huge loop in each of its five outer faces, designed for a cross-bow 16 feet long: these loops, splayed throughout and fan-tailed at top and bottom, are the finest examples of cross-loops left in England, and declare the main purpose of the tower at once. In later years, when the cross-bow was out of fashion, the interior of the tower was somewhat altered, and a fireplace inserted.

The best examples of curtain-towers, both abroad and in England, form complete cylinders, like the angle-towers at Coucy, or polygons, like some of the towers at Carnarvon. But room was spared if the cylinder or polygon was left incomplete, and its inner face made nearly flush with the curtain. The two towers on the curtain of the inner ward at Pembroke projected with semicircular curves into the outer ward, but were flat at the back: the south tower covered the gateway of the inner ward, which was not in the face of the wall, but round an angle. The towers of the outer ward, on the other hand, are mostly complete cylinders: the stairs were vices contained in rectangular turrets on one side, the outer walls of which are curved to meet the circumference of the towers (181).[266] Marten’s tower at Chepstow, and the towers of the curtain of the fine early fourteenth-century castle of Llanstephan, are cases in which the projection of the tower is only external. The tower which caps the eastern angle at Llanstephan is a half-cylinder, springing, not directly from the curtain, but from a broad rectangular projection on its face.[267] The variations which might be noticed in the attachment of towers to the curtain are manifold: but, as time goes on, the ordinary curtain-tower, where it was not placed at an angle of a ward, stood flush with the curtain on its inner side (228). Where the tower stood on the curtain by itself, unattached to other buildings within the castle, there was usually an entrance to the basement direct from the bailey, on one side of which a vice in a turret attached to the tower rose to the upper floors and roof, communicating on the level of the first floor with the curtain. The doorway opening on the curtain was fitted with a strong door, and, in Marten’s tower at Chepstow castle, where the tower was of special importance, standing as it does at the lowest and most vulnerable point of the site, was provided with a portcullis.

There were cases, however, especially in walls of towns, where the curtain-tower, although projecting outside and above the wall, and covered with a timber roof, was left open at the gorge or neck, where it was flush with the curtain, so that it was simply an open tower, with a platform on the first floor, level with the rampart-walk, and a rampart-walk of its own at the level of its battlements. Such a tower could be actively employed in time of war, and had all the advantages of the ordinary closed tower in flanking the wall and cutting the rampart-walk up into sections. The numerous towers of the walls of Avignon, between the gatehouses, were arranged thus.[268] At Conway, the semi-cylindrical towers of the town walls, of which there are twenty, and the similar towers which flank the gatehouses, are open to the town: one tower only, on the south-west side of the town, where the wall turns to join the castle, is walled at the gorge. The walls of Chepstow provide further examples of open towers. At Carnarvon (251), the round towers on the face of the town walls are open, but the angle-towers were closed; and that at the north-west angle was entered through the town chapel, which was built against the curtain at this point. The open tower was not, as a rule, used in castles: even the small towers which flank the outer curtain at Beaumaris have a wall continued across the gorge.

Every large castle was provided with a postern or sally-port. This was generally a small doorway, preferably in the base of a tower, but often in the curtain, opening on the least frequented side of the castle. In time of siege, in a castle of the ordinary plan, a postern might easily be a source of danger; and its employment in the scheme of defence was incompletely understood at first. But it was useful for the conveyance of provisions to the castle; and a postern, as at Warkworth, is often found in connection with a kitchen or store-room. Where a castle stood near a river, a water-gate, communicating with a private wharf was made. At Pembroke, where the castle stands between two water-ways, there were two water-gates, one in the south side of the outer ward, the other, as already mentioned, formed by walling in the mouth of the cave below the great hall. For the scientific employment of the postern, however, we have to look to the great castles of the later part of the thirteenth century, in which the means of defence described in this chapter were perfectly co-ordinated; and, with the introduction of a new plan, the last signs of a merely passive strength vanished from the castle.