CHAPTER IVTHE PROGRESS OF ATTACK AND DEFENCE

Theearthwork fortifications, the progress of which we have traced up to the Norman conquest, were of a very simple kind. It is obvious that, in the history of military architecture, any improvement in defence is the consequence of improved methods of attack. The stone-walled town of the middle ages, the castle or private citadel, with its curtain wall and the subdivision of its enclosure into more than one bailey, succeeded the palisaded earthwork as a natural result of the development of the art of siege. Against an enemy whose artillery was comparatively feeble the stockaded enclosure was effective enough: slingers and bowmen, working at close quarters, might do damage to the defenders, but the palisade on the bank, divided from the besiegers by a formidable ditch, was proof against missiles launched against it by individuals, and could be carried only by a determined rush, or if it were not sufficiently protected against fire. Modern warfare against uncivilised tribes has shown that a stronghold defended by a thick hedge is a serious problem to a besieging force. If, under modern conditions, the stockade is a barrier to troops equipped with powerful firearms, the difficulty which it afforded to the early medieval warrior is obvious.

The age of firearms, however, which brought the death-blow to medieval siegecraft, was long in coming; and meanwhile the progress of the science of attack depended upon the improvement in methods which could be employed only in close proximity to the besieged stronghold, or within a very limited range. Engines for hurling stones or javelins increased in size and strength. Devices were brought into play for scaling or undermining the defences of the town or castle. The attack was directed against the defences rather than against the defenders. A casual stone might do injury to the medieval soldier, or an arrow might pierce between the joints of his harness; but his armour, which became more heavy and more carefully protected as the chance of risk from such missiles increased, made loss of life in the course of a siege a misfortune rather than an inevitablecontingency. His first anxiety, therefore, was to make the defensive works which sheltered him impregnable. As the enemy multiplied his designs against the palisaded enclosure, the palisade gave place to the stone wall; as the enemy’s means for prosecuting his attempts increased in power, the wall increased in height and strength; and at last, during the transitional epoch in which firearms gradually superseded the older and more primitive weapons of attack, the wall presented to the besieger a thoroughly guarded front which rendered his medieval siege tactics obsolete, and called for new developments in his craft.

The progress of fortification under these conditions will be the subject of the remaining chapters of this book, with special reference to the castle, in the defences of which the military engineers of the middle ages displayed the epitome of their science. Before we proceed, however, to the growth of the stone-walled castle, some description is necessary of the improvement in siege-engines and methods of attack by which its development was governed. It must be kept in mind that the siegecraft of the middle ages advanced upon lines that were by no means new. Its engines, its devices for breaking down or scaling walls and towers, were not new inventions, but relics of Roman military science. With the decay of the Roman power in western Europe, these materials of warfare, unknown to the Teutonic conquerors of Britain, had fallen into disuse. Preserved in the east by the Byzantine empire, the inheritor of Roman civilisation, they became familiar to the barbarians who overran Europe in the dark ages; and their revival in the parts of Europe most remote from the historic centres of Roman influence was due in no small measure to the adoption of traditional siegecraft by the invading tribes which had come into conflict with Byzantine strategy. So far as England is concerned, the first advance in the art of attack was the direct result of the Norman conquest; while subsequent improvement in western Europe generally was primarily due to the knowledge of eastern warfare gained during the Crusades. A slight retrospect, under these conditions, is desirable, which will give us some insight into the methods of siegecraft during the period of whose strongholds and art of fortification we already have seen something.

Many classical texts, from the time of Cæsar to the latest days of the western Empire, supply us with authority for Roman military methods. No passage throws fuller light on their siege practice than Cæsar’s description of his siege of Alesia in Burgundy, the hill fortress occupied by Vercingetorix.65The lines which were first drawn round the stronghold by Cæsar were eleven miles in circuit, and communicated with three camps, on hills of a height equal to that of the hill of Alesia. Along the lines there were twenty-threecastella, small forts to hold pickets, and temporary examples of the type of which the “mile-castles” of the Roman wall were permanent instances. The stubborn resistance of Vercingetorix and the prospect of the arrival of a relieving army, however, gave Cæsar occasion to elaborate his lines, the character of which is very minutely described. They consisted of an earthen bank with a ditch 20 feet broad, 400 feet in front of it on the side towards the besieged stronghold. The ditch was dug with perpendicular sides: its distance from the bank was a precaution against sudden attacks of the enemy, and placed the bank out of the range of casual missiles. The space between the bank and ditch was not a level “berm,” but was furrowed by two ditches, 15 feet in breadth and depth, of which the inner was wet, the water of the neighbouring streams being diverted into it. Behind the inner ditch rose the earthenaggeror bank, to the height of 12 feet. Thevallum, the rampart on the top of theagger, was of a type common in early warfare and for many centuries later, consisting of a breastwork of interlaced twigs stiffened by a row of palisades. The hurdles of the breastwork were finished off with battlement-like projections: at intervals there were tall uprights with forked tops, which were calledcervior “stags,” and acted aschevaux-de-frisealong the whole rampart. There were also towers, obviously temporary constructions of timber, at distances of 80 feet from one another. This, however, was not enough. Cæsar aimed at holding his lines with as few men as possible, so as to allow the rest to do the necessary foraging at a distance. He therefore proceeded to sow the approach to the lines with pitfalls. Five ditches, 5 feet deep, were dug out and filled with upright stakes sharpened to a point and fastened together at the bottom by continuous cross pieces. In front of these were three rows of pits, 3 feet deep, arranged in a series ofquincuncesor saltires: in these were placed smooth sharpened stakes, so that little more than their points stuck out of the ground, and the pits were then covered over with twigs and brushwood. The eight rows formed by these obstructions were each 3 feet apart. The whole arrangement, producing the effect of a row of fleurs-de-lys, was calledlilium: to the stakes the soldiers gave the name ofcippior “grave-stones.” On the opposite side of thevallum, where an attack from a relieving army was expected, a similar arrangement was made. Also, in front of thelilium, wooden cubes with hooks fastened into them were hidden in the ground, bearing the appropriate name ofstimuli.

Cæsar’s method of besieging Alesia was dictated by the probability that, with an enemy on both sides, he would have to stand a siege himself. After a doubtful battle, the Gallic army of relief made a night attack on the lines, in which they found to their cost the effectiveness of Cæsar’s death-traps. They brought with them hurdles, with which to help themselves across the ditches, and scaling ladders and grappling hooks, with the help of which they might climb or pull down the rampart. Their weapons were slings, arrows, and stones, to which the Romans replied with extemporised slings and spears. They suffered two repulses, and then turned their attention to the weakest of Cæsar’s camps, while Vercingetorix left Alesia to attack the rampart. His force brought hurdles with long balks of timber to form a footway across them, mantlets, or coverings under which an attacking party, sheltered from Roman missiles, could undermine or make a breach in Cæsar’s earthwork by the use of a bore, and hooks with which to cut down the rampart on the top of the earthen bank. The attack was long and determined. The Gallic pioneers filled up Cæsar’s fosses, so far as they could, with earth, and themselves raised a mound from which his devices of defence were easily seen. Where his lines were on level ground, they were too formidable to attack: on the steep slopes of the hills, on the tops of which his camps were pitched, there was more chance for an enemy. Here the fiercest fighting took place: the towers of thevallumwere assailed with javelins, the ditch was filled, and an attempt was made to tear down the palisade and breastwork. Labienus, unable to hold the lines, sent a message to Cæsar, whose intervention with his cavalry turned the day and brought about the total defeat of the Gallic army and the surrender of Vercingetorix.

The account of the siege of Marseilles by Gaius Trebonius inB.C.49 gives us many of the methods employed by the Romans, and by Byzantine and medieval engineers after them, in the siege of a walled town.66Marseilles was no mere hill stronghold like Alesia: it was a strongly fortified seaport town, well equipped for war with engines which hurled pointed stakes 12 feet long against the besiegers, as they threw up their earthen bank round the landward side of the city. Treboniushad to make the line of penthouses (vineæ), by which his pioneers were protected, of more than ordinary thickness to withstand these missiles. In advance of the bank, a body of men, sheltered by a large penthouse (testudo) levelled the soil. While this leaguer was established on the landward side, Brutus gained a naval victory over the Massiliotes, who nevertheless continued to hold out against the besiegers. The right wing of the Roman army was especially open to attack from the city; and on this side the besiegers built a tower of brick, to serve as a base of operations and a refuge from attack. This tower, which was raised to a height of six stories, was built by workmen who were sheltered by hanging mantlets of rope. A roof was made of timber, covered with a layer of bricks and puddled clay, to protect it against fire, and with raw hides, to make it proof against darts and stones. As the tower grew, this roof, from which the rope mantlets depended, was raised by levers and screwed down as a covering to each story in succession. When it was nearly completed, a wooden penthouse known as the mouse (musculus) was constructed, consisting of a gallery 60 feet long, with a gabled roof, which was covered, like that of the tower, with bricks, clay, and hide. This was moved forward on rollers to the nearest point in the city-wall. It withstood the huge stones which were cast upon it; lighted barrels of pitch and resin, hurled from the wall, rolled off its sloping roof and were pushed to a safe distance by the men inside, armed with poles and pitchforks. Covered by their friends’ fire from the brick tower, the soldiers in the mouse were able to sap with their levers and wedges the foundations of the tower on the wall, and managed to effect a breach. The defenders submitted, and asked for a truce until Cæsar arrived; but, taking advantage of the interval, they made a treacherous sally from the city, and, aided by a favourable wind, burned down the besiegers’ constructions, including the mouse and the brick tower, and destroyed their machines. Trebonius, however, lost no time in constructing, instead of his earthen bank, a strong wall of countervallation, composed of two parallel walls of brick, each 6 feet thick, with a timber floor above. This quickly brought the defenders to their senses, and they reverted to their old conditions of peace. In this account the devices which play the chief part are met again in numberless medieval sieges. The lines of countervallation, the successful sapping operation, appear, for example, in the tactics of Philip Augustus: the besiegers’ brick tower is met again in William Rufus’ timber castle at Bamburgh: the engines of war and the protected penthouses are commonplaces of medieval warfare.

The bare record of the Anglo-Saxon Chronicle throws little light to speak of upon the strategy or military skill of the Danes. Nor does the lyric form of the songs which celebrate the fight at Brunanburh and the battle of Maldon allow of that definiteness of detail which the student requires. More definite, although not unencumbered by rhetoric, is the account which Abbo, the monk of Saint-Germain-des-Prés, gives of the siege of Paris by the Northmen in 885-6.67The city of those days was confined to the isle still known as La Cité, and was united to its suburbs on the mainland by two bridges, where now are the Pont-au-Change and the Petit-Pont. The approach to each bridge was guarded, on the mainland, by a tower ortête-du-pont. The attack of the Normans was directed against the northern tower, the construction of which had not been finished. It is curious to notice how they concentrated themselves on single points in the defence, neglecting the prime necessity of closing all lines of communication to the defenders. They came up to the tower with their ships, which were seven hundred in number, not counting sailless boats, battered it with their engines, and hurled darts at its defenders. The tower was shaken, but its foundations stood firm: where the walls threatened to give, they were repaired with planks of timber, and the tower was raised by these wooden additions during a night to one and a half times its former height. At daybreak the Northmen again began the attack. The air, says Abbo, was full of arrows and stones flung from slings and from theballistaeor hurling machines. During the day the heightened tower showed signs of succumbing to the enemy’s fire and their mining efforts. Eudes, the brave defender of the town, poured down a mixture of burning oil, wax, and pitch, which quenched the enthusiasm of the besiegers, and cost them three hundred men. On the third day, the Northmen established their land camp on the northern bank of the river, near the church of Saint-Germain-l’Auxerrois. The camp was probably ageweorcsuch as they wrought by the Thames or the Ouse, but it was girt, not with an earthen rampart, but with walls of clay mingled with stone. From this centre they cruelly ravaged the surrounding country during the remainder of the siege. Having thus established their base of operations, they returned to the attack of the tower. Their devices were the common devices of Roman warfare, which naturally would recommend themselves to the assailants of the dying Roman civilisation. We hear of the three great battering rams which they prepared, and moved up against the wallsunder the shelter of wooden penthouses on wheels, of the bores brought up to undermine the tower by men moving under wicker mantlets covered with raw hides, of themanganaor stone-throwing machines used by the defenders, and of the forked beams let down from the tower to catch the heads of the battering-rams and render them powerless. Some of the Northmen worked at filling up the ditches with whatever came to hand, earth, leaves, straw, meadow grass, cattle, even the bodies of captives. Still the city held out, and Eudes managed to slip through the enemy’s lines and reach Charles the Fat with a request for relief. On his return the Northmen tried to intercept him: he got back safely into Paris, while a relieving force attacked the enemy and drove them back on their ships. When Charles the Fat arrived he established his camp on the southern slopes of Montmartre; but he was content, after a general attack upon the city had failed, to let the Northmen go, taking with them an indemnity of seven hundred pounds, and promising to leave the kingdom in March. They, however, made an attempt to reach the upper Seine in boats, as the larger vessels could not clear the bridges, and so proceed to pillage Burgundy. Their purpose was discovered: the defenders of Paris launched arrows at them from the walls, and a chance dart killed their pilot. For a time their onward course was checked, but a series of such assaults could not be sustained by the French. Eudes, elected king, neglected the conflict, and gave words for deeds. “Their barks,” says Abbo, “were in crowds on all the rivers of Gaul.” He ends his poem with a call to France to give proof once more of those forces which she had used in the past to conquer kingdoms more powerful than herself. “Three vices,” he cries, “are causes of thy ruin: pride, the shameful love of pleasures, the vain lust of gorgeous apparel.” The same words might have been said to the English a hundred and twenty-five years later, when Swegen and Thurkill were gripping London between their two armies.

A short passage in the Anglo-Saxon Chronicle affords some help to the question of Danish strategy. London bridge, like the two bridges of Paris, was an obstacle to the long Danish ships with their sails. In 1016, however, the Danes managed to drag their ships round the south side of the bridge, apparently by making a ditch on that side of the river. They then proceeded to make entrenchments about the city, their headquarters being thus removed above bridge. There is no reason to doubt that the London which they thus beset was a stone-walled city, the Roman Londinium which Alfred had repaired. So was Paris, and so were a large number of the towns of France, whose wallshad been set in repair by their bishops or lay lords. We read of Saint Didier, bishop of Cahors 630-55, that he “enlarged, built, and made strong Cahors with abundant labour, and a notable work of defence, fortifying gates and towers with a girdle of walls compacted of squared stones.” In the next century the Saracen invaders of southern France restored the Roman walls of Narbonne, and checked the advance of Charles Martel into Spain.68But for the many instances in which the fortifications of Roman cities in France played a part in the warfare of this troubled epoch, there are few in England. Theburhsof the Danish wars were, with the exception of London, Towcester, Colchester, and a few more, not stone-walled cities of Roman foundation, such as those which in France were the natural prey of the Norman marauders, but villages or small towns which had grown into existence for the most part since the Saxon conquest, and owed their strength to walls of timber. In France military art, as regards both fortification and siege-craft, was altogether on a higher plane. The break of continuity caused by the extinction of Roman civilisation in England produced a stage in the development of attack and defence to which contemporary French history affords no parallel. It is not till a later period that the finished methods employed by both sides in the siege of Paris were used in English warfare.

The cases hitherto quoted refer to sieges of towns; and, as we have seen, the castle or private fortress which plays so prominent a part in medieval strategy was the result of the growth of the feudal system, and takes its place in history at a comparatively late period. A fortified town of Roman origin possessed itsarxor citadel: this was, as it were, the keep of the walled enclosure, to which the defenders could retire if the outer defences of the town were taken. A castle, however, was a distinct enclosure, which frequently occupied a portion of the area of a walled town, but had its own outer lines of defence before the keep could be reached. The Norman conquerors of England, regarding the castle as the main seat of defence and object of attack, directed their attention to its fortification; and thus the defence of the town or village in or near which the castle stood became of secondary interest. We usually find that, where a castle forms part of the defences of an English walled town, the castle has been surrounded with a wall and provided with its necessary defences before a wall has been built round the town in place of the earlier palisade. In spite, however, of this change in the nature of the besieged stronghold,the object of attack was still a fortified enclosure. The methods of siege developed along the old lines; and the defences applied to the castle were those which, on a more extended scale, were applicable to the town.

The warfare of the eleventh and twelfth centuries was to a great extent a succession of sieges of castles, by direct attack or by blockade. In 1083 William the Conqueror, besieging Hubert of Maine in the castle of Ste-Suzanne, did not venture to attack the wooded precipice on which the castle stood, but entrenched his army within earthworks in a neighbouring valley. The blockade lasted three years, and the advantage lay much on the side of Hubert, so that eventually the Norman army, after a desperate attack had failed, withdrew.69The chief feature of the blockade was the construction of an opposition castle,70a method employed upon more than one occasion by William II., who, in 1088, compelled Odo to surrender Rochester castle by making twocastellaupon his lines of communication.71In 1095 William II. besieged Robert Mowbray in Bamburgh castle. The great rock, with its girdle of sea and marsh, did not lend itself to direct attack, and William compelled its surrender by building a “new fortress,” which took the form of a timber castle, probably of the ordinary mount-and-bailey type, and was nicknamed Malvoisin, the “ill neighbour.”72From this particular instance, the name ofmalvoisinhas been applied generally, without sufficient reason, to the wooden towers which were sometimes constructed to shelter a besieging force. As a matter of fact, Malvoisin was merely one of many nicknames which were given, in individual cases, to such besiegers’ castles,73and was no more a generic term than is Château-Gaillard.

Until the end of the eleventh century, when the first Crusade taught western warriors the use of more advanced siege-engines, the methods of attack upon a castle seem to have been of a very simple description. Earthworks defended by timber could be gained by a rush and hand-to-hand fighting; while fire would always be fatal to a wooden stronghold ill provided against it. The Bayeux tapestry shows us none of those siege-machines which were employed more and more frequently against stonecastles during the next century; and, although the Conqueror’s army seem to have employed an elementary form of stone-throwing machine, handled, like the later cross-bow, by individual soldiers, and other devices more familiar in later times,74such machines can hardly have been common. It was, no doubt, their growing frequency at the beginning of the twelfth century which made stone walls imperative for the protection of a castle. We have seenballistaeand other siege-engines of Roman origin used by the Northmen at the great siege of Paris in 885; but such engines were certainly not in common use in western Europe before the period of direct contact with Byzantine civilisation. Ordericus Vitalis mentions the construction of such machines, a “belfry” on wheels and devices for hurling large stones, by Robert of Bellême’s engineer at Bréval in 1093, as though they were a novelty, and says of the engineer himself that his sagacious ingenuity had been of profit to the Christians at the siege of Jerusalem.75

Suger’s detailed account of the attack made by Louis VI. upon the castle of Le Puiset in 1111 may be taken as a fair description of the methods employed by the besiegers and defenders of an ordinary castle of earthwork and timber. The king brought numerousballistaeto the attack, but we have no indication as to their precise nature: the main weapons employed were the bow, sword, and shield. The besieged came out of the castle to meet the king; but, amid a hail of arrows from both sides, were driven back through the main gateway, which was possibly, as at Tickhill,76the only stone defence of the enclosure. From the rampart of their stronghold, they hurled down wooden planks and stakes upon the king’s knights. The besiegers, throwing away their broken shields, made use of the missiles to protect themselves and force the gateway. Carts laden with dry wood smeared with fat were brought up to the doors, and a struggle took place, the royalists trying to set the wood on fire, the defenders trying to put the fire out. Meanwhile Theobald of Chartres made an attack on the castle from another quarter, attempting to climb the steep scarp of the bailey. His followers, however, were too hasty: many fell back into the ditch, while others were surprised and killed by horsemen ofthe enemy, who galloped round the defences of the castle to keep out intruders. The royalists had almost given up hope, when a priest, bare-headed and holding before him a piece of wood as an extemporised mantlet, reached the palisade, and began to tear away the planks which covered the spaces between the uprights. He was soon joined by others, who cut away the palisade with axes and iron tools. The royal army poured into the castle, and the defenders, taken between the entering force and Theobald’s men, retired into the timber tower on the mount, but surrendered in fear. The king burned the castle, but spared the donjon.77

The assault upon a stone castle or walled town was conducted by direct attempts upon the walls themselves, for which movable machines were necessary, and by throwing stones or inflammable materials into the besieged enclosure from stationary machines. The chief engine used directly against the walls was the battering-ram, an enormous pole, furnished with an iron head. Hung by chains within a wooden framework placed on wheels, it was brought up to the wall, and driven against it again and again. The men who worked the ram were protected by a pent-house with a rounded or gabled top, called the “tortoise” (testudo), which covered the machine and its framework. The roof of the “tortoise” was made very solidly, to resist missiles thrown from the ramparts, and the whole was covered with raw hides or some other incombustible material, as a precaution against fire thrown by the defenders (69).78

Battering-ram protected by pent-house and mantlets

While the ram delivered its blows upon the face of the wall, sappers and miners, sheltered by a smaller pent-house, known as the “mouse,” “cat,” or “sow,” made their attack upon the foundations with the bore (terebra), a heavy pole with a sharp iron head, which slowly broke up the stonework and hollowed out a cavity at the foundation of the walls (70). This work was assisted by sappers, who, advancing to the wall beneath the shelter of inclined frames of timber or wicker-work, known as mantlets, which they wheeled in front of them, hacked away the stone-work with picks. When a sufficient hollow had been made, the miners underpinned the wall with logs, set fire to them, and retired. This device was constantly used throughout the middle ages to effect a breach, and was successful at Château-Gaillardin 1204,79and on other occasions; but it obviously must have taken much time, and must often have failed of its purpose.

Before, however, the movable engines could be brought to play upon the stonework, it was necessary to fill up the ditch in front of the walls. This work was done by soldiers, who, under the protection of mantlets, flung into the ditch all the loose material on which they could lay hands. When the Danes used their battering-rams against the northerntête-du-pontat Paris, the first thing which they attempted to do was to fill the ditch, using even the dead bodies of their captives when other material failed.80At Jerusalem in 1099, before Raymond of Toulouse could bring up his “timber castle”81to the walls, a deep natural hollow had to be filled. The work took three days and nights: every man who put three stones into the hollow was promised a penny.82Philip Augustus in February 1203-4 began his operations upon Château-Gaillard by filling the ditch between the outer ward and his lines, while his catapults played upon the masonry from a distance and protected the workers between them and the wall.83

Bore protected by mantlets

While the battering-ram, the bore, and the mine threatened the stability of the walls, parties of the besiegers attempted to force an entry into the stronghold. The simple method of bringing up fuel to the main gateway, and burning down the door, was frustrated, in process of time, by greater attention to the defences of the gateway, and the reinforcement of its doors by herses or portcullises.84Scaling-ladderswere moved up against the walls: the daring spirits who climbed these drew up with them other ladders, by which they could descend into the enclosure. Another method of scaling walls was by the movable “belfry,” a tower of several stories, in each of which a number of men could be sheltered. The floor of the uppermost stage of the tower was approximately on a level with the top of the ramparts, and a drawbridge thrown out from it, when it was wheeled close to the wall, formed a passage for the besiegers. The occupants of the lower stages could mount by stairs to the top floor, and thus a considerable body of men could come to close quarters with the defenders (72).85These movable towers could be quickly constructed, where wood of sufficient scantling was procurable. Philip’s belfries at Château-Gaillard were composed of tree-trunks, untouched by the plane: all that the carpenters had done to smooth them was to cut off the branches with an axe.86In early instances of the employment of such towers, they seem to have been chiefly used for bringing the small artillery of the besiegers close to the walls. At Marrah in 1098, the Crusader Raymond of Toulouse had a very lofty wooden “belfry,” of a height equal to that of the towers on the town wall, made upon four wheels. Huge stones were hurled and arrows shot from it upon the defenders of the walls, and grappling-irons were thrust out to catch unwary persons with their hooks. The walls were eventually climbed by scaling ladders of the ordinary kind: if there was a drawbridge in connection with the machine, it does not seem to have been used.87Antioch, earlier in the same year, was entered by scaling ladders.88The belfry used by Henry I. at Pontaudemer in 1123 was a movable tower, but was not used for purposes of scaling. It was actually 24 feet higher than the rampart: bow-men and arbalasters directed their arrows and bolts from it upon the defenders, while others threw stones down from it.89Not even at Château-Gaillard is there much reason to suppose that Philip used his belfries to scale the walls. The miners and catapults did the chief work, by opening breaches in the masonry of the outer and inner wards: the middle ward alone was gained by an escalade, and this was effected by a small body of men, whoclimbed through unguarded openings in the substructure of the chapel, and so were able to unbar the gates of the ward to the main body of the army.

Besiegers scaling walls from movable belfry

The great siege-engines, capable of shooting stones or bolts, which were often heated red-hot in an oven before delivery, from a considerable distance, did their work from the background. The men who looked after them were protected by a palisade, placed in front of the engines; this was the case with Philip’s engineers at Château-Gaillard. These machines are often indiscriminately called “stone-throwers” (petrariae,pierrières) or catapults; and accounts of them differ very considerably. It is clear that, in Roman and Byzantine warfare, the two main types of engine were the stone-throwing machine, known later as the mangon or mangonel, and the machine for shooting javelins, known asballista.90The first consisted of an upright flexible beam between two solid upright posts. Cords were stretched from post to post and wound round the beam. The beam was then drawn back with the aid of winches and a stone placed in a hollow in its head; it was then suddenly let go, so that the twisted cords slackened, and the stone flew towards its mark, describing a high ellipse in its flight. The force by which theballistawas worked, depended, not on twisted cords, but on the tension of the cord which joined the two extremities of a great bow, and was attached to the movable grooved piece in which the javelin was placed. The tension released, the javelin was discharged. While theballistacould be discharged with a definite aim, the aim of the stone-throwing machine could be only general, and its chief use was to cast stones which, by their elliptic flight, dropped inside the walls of the besieged place.91

Engine for shooting javelins

Stone-throwing engine

Theballista, which was simply a huge bow, capable of shooting enormous bolts by the tension of a horizontal cord, was developed upon a small scale into the cross-bow or arbalast, which could be carried and managed by one man. The cross-bow was invented, or at any rate re-invented, in northern Europe towards the endof the eleventh century, it was employed in the first Crusade, and struck the Byzantines as a novelty.92The development of the larger engines seems to have proceeded with a view to stone-throwing, and combinations of the machines mentioned above may have been employed for this purpose.93Viollet-le-Duc, in his elaborate reconstructions of siege-machines, shows, for example, a mangon with a central upright post, working on a pivot, in a slot near the top of which is fixed a javelin. This post is strengthened by two diagonal beams fixed to theback of the framework, which moves on the same pivot, at the foot of the machine. Between these the flexible beam which propels the javelin is fastened by a cord working through a pulley to a winch turned by a man, and a bundle of cords is tightly twisted round the central post and the beam (74). He also shows a large stone-throwing engine on a wheeled carriage, which, in addition to an apparatus of twisted cords held in place by a system of ratchet wheels, and bound round the movable beam, has a cord stretched round the back of the beam, and connected with two huge springs forming a bow. The centre of the bow is a massive upright framework of wood, which acts as a buffer to the beam, when it is allowed to flyforward and discharge the stone (74). Minute as these reconstructions are, they seem to improve upon the data supplied by medieval writers and the pictures in MSS. Guillaume le Breton, the panegyrist of Philip Augustus, describes the stone-throwing machine used at the siege of Boves in 1185, as a great sling worked by several men, which threw immense rocks of great weight. The beam to which the projectile was attached worked on an axis, and was dragged backwards to the ground with ropes, and then set free.

Trébuchet or Slinging machine

Trébuchet with ropes attached to counterpoise

This description suggests that the beam, balanced on an axis, and needing several people to attend to the discharge at one end, was worked by a counterpoise at the other. This was the case with the developed slinging machine, known astrébuchet. A pole, working on a pivot between two upright stands, was weighted at one end with a heavy wooden chest, filled with earth, which kept the pole, when not in use, in a vertical position. To the other end was attached a long sling, capable of containing large stones. When the tension of the ropes which dragged the pole backwards and lifted the counterpoise was released, the counterpoise fell heavily, bringing the pole abruptly back into position, and the sling, describing a circle in the air, let fly the stone when it reached the summit of the arc (75). Variations of this form of catapult, which became general in the thirteenth century, are found (76); the machine known ascabuluswhich Philip Augustus used with excellent effect against the strong inner wall of Château-Gaillard, was possibly worked upon the principle of counterpoise.

Against these modes and machines of attack the defenders of a castle had to contend. The obvious means of defence was to oppose to the enemy a thickness of wall which would be proof against the blows of the ram or the slow labour of the pick. But even the very strong inner wall at Château-Gaillard, which was constructed with the special object of resisting these engines,yielded to the miners, reinforced by the great slinging machine. In this instance the castle had undergone a long blockade; its communications had been cut off some months beforehand; and the garrison was greatly reduced in numbers. The lesson of the siege was that against a persistent and well-conducted blockade mere passive strength was of little avail. Here, too, the defenders, driven back from one bailey to another, seem to have renounced the opportunity of final shelter afforded them by the keep, and to have made an attempt to evacuate the castle by a postern before they fell into the hands of the enemy.

Aigues-Mortes

Carcassonne

Château-Gaillard, however, and the castles of its period will be discussed in detail in the sequel. At present, we are concerned with the direct methods employed to meet the attack of siege-engines and attempts at escalade. Against the great catapults the besieged were practically powerless. The use of such machines upon the walls themselves was as dangerous to the stability of the masonry as their use by the enemy, and hastened the chance of a breach: they could not be employed from the interior of the enclosure, without endangering the defenders on the rampart.94The summit of the rectangularkeep of the twelfth century was never constructed as a platform for artillery: here, again, engineers probably feared the effect of the constant vibration upon a flat wooden roof, and were content to conceal their ridged roofs within high ramparts. The main arm of defence which could be employed by the defenders was the cross-bow. Their superior position upon the ramparts enabled them to throw down stones and burning material upon the assailants engaged at the foot of the wall, and the wheeled belfries formed a direct target for their arrows. The ram couldalso be paralysed by letting down grappling-irons or beams with forked heads, which gripped and disabled it; or sacks of wool or earth could be lowered to meet its strokes. The assailants, however, worked under their defences of pent-houses and mantlets, the solid tops and sloping surfaces of which were specially devised against the shock of stones and arrows; while, as we have seen, their coverings were so protected that it was difficult for them to catch fire.

Parapet defended by hoarding, showing elevation, section throughhourdandcoursière, and method of construction

Laval

The first improvements in defence, designed to meet an improved attack, consisted in the protection of the ramparts. Behind the outer parapet of the wall was the rampart-walk, a level path along the top of the wall, which was sometimes protected by a parapet in the rear. From an early date in stone fortification, it was customary to break the upper portion of the parapet at intervals by openings called crenellations, through which it was possible for an archer to command a limited part of the field at right angles to the wall.95The crenellations, however, were narrow compared with the unbroken parapets between them, and, even in advanced examples of fortification like the ramparts of Aigues-Mortes (77) and Carcassonne (78), these unbroken pieces are still very broad, although they are pierced by arrow-slits. Even allowing for an arrow-slit between each crenellation, the foot of the wall could not be commanded from behind the parapet. In time of siege, then, it became customary to supply the walls with projecting wooden galleries, known as hoardings or brattices (hourds,bretèches), which could be entered through the crenellations. The joists of the flooring passed through holes at the footof the parapet, and were often common to the outer gallery and an inner gallery (coursière) covering the rampart-walk. Both galleries had a common roof.96In the floor of the outer gallery, between the joists, were holes, through which missiles could be directed upon the besiegers at the foot of the wall; while slits in the outer face were still available for straight firing. The defenders of the ramparts were thus able to work under shelter, with some command both of the field and the foot of the wall. Thedefensive advantages of this scheme are obvious; but the galleries were also liable, although the usual precautions for their covering were taken, to destruction by fire, whether from arrows tipped with burning tow, or the more formidable red-hot stones flung by catapults. In any case, the catapults were a serious menace to their solidity.

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