It was probably in the year 120, three years after his accession to the empire, that Hadrian visited Britain. The journey may have been only part of his pre-arranged tour through the western portion of his dominions, but it is also possible that it was the result of some recent and special disaster in Britain to the Roman arms. Some forty or fifty years afterwards the orator Fronto alluded to “the great number of soldiers slain by the Britons during the reign of Hadrian,” and it is allowable at least as a matter of conjecture to couple these words with the ominous disappearance of one of the legions stationed in Britain from the army list of the empire. The unlucky Ninth legion, once quartered at Lincoln, afterwards at York, had been, as we have seen, nearly destroyed in the insurrection headed by Boadicea. It had again suffered most severely, under Agricola, from a night attack made by the Caledonians before the battle of Mons Graupius. And now, just about this time, either in the later years of Trajan or the earlier years of Hadrian, it vanishes clean out of the lists of the Roman army and is replaced by the Sixth legion, surnamed the Victorious, which was brought over to Britain and stationed at Eburacum. There is some discussion as to the earlier cantonment of the legions, whether four or three, that had been quartered in Britain, but as to the general question of their allocation during, at least, the second and third centuries of our era there can be no doubt. The Second legion (Augusta) at Isca (Caerleon-upon-Usk); the Sixth (Victrix) at Eburacum (York), and the Twentieth (Valeria Victrix) at Deva (Chester), have left abundant tokens of their long-continued presence.
From all these legions, however, considerable drafts were taken to assist in the building of the wall from Tyne to Solway, the existing remains of which must now be described. At the two ends of its course, where it has had the ill-fortune either to meet with the fierce industrial energy of the dwellers by the estuary of the Tyne, or to attract the envious glances of the farmers of fertile Cumberland, the wall has practically ceased to exist, though it has seldom passed that way for more than two or three miles without leaving some traces, however faint, of its presence to reward the quest of the earnest antiquary. But in the central part of its course, where it has left the busy haunts of men and climbed the bleak moorlands and the steep basaltic cliffs of Western Northumberland and Eastern Cumberland, it still exists in what its great historian, Dr. Bruce, used to call “an encouraging state of preservation”. For twenty miles or more it goes striding over mountain and moor, religiously climbing every cliff and dipping down into every hollow of the sharply outlined, serrated, whinstone range. Sometimes we see only the rough rubble-work which formed the core of the wall, but more often the well-hewn square blocks which faced its northern and southern sides are still visible. The height attained by it is in one or two places as much as nine feet, but its more usual altitude is four to five feet. It was probably when perfect about seventeen feet high; and its width, as we know from the existing remains, varied from six to eight feet. The line of the wall once fixed, its builders seem to have pursued a nearly uniform plan, regardless of the help which they might have derived from natural defences. Thus in one place it crowns the heights of some steep basaltic cliffs at whose feet lies a small Northumbrian lake. No desperation of bravery would ever have caused a Brigantian chief to dash across that lake and climb those pinnacles of columnar basalt: still even here the wall pursues its undeviating course, and, so far as we know, retained its undiminished height. It is possible, however, that in such a case as this it was meant as a defence, not against barbarians, but against the weather. Snowstorms sometimes sweep violently across these bleak moorlands, and it may have been thought desirable to provide the Roman sentinel, pacing backwards and forwards between camp and camp, with some shelter from their fury.
Along the line of the wall are situated fortified enclosures of three kinds which now go by the names of camps, mile-castles and turrets. The camps, of which there were seventeen, between Tyne and Solway, and which were probably called by the Romans Prætenturæ or Stationes, vary in size from three to six acres. They were destined for the housing of one cohort—a body of men varying in size from 600 to 1,000—with, no doubt, a certain number of camp-followers, and in some cases a considerable troop of horses. Public buildings, known by antiquaries as the prætorium, the forum and the like, are to be found generally in the centre of the camp, sometimes on the side most exposed to the enemy’s attacks: and the quarters of the officers may generally be distinguished from those of the common soldiers by the elaborate arrangements for warming them, known as hypocausts. In these the floor of the room is supported on ranges of short pillars (generally about eight or nine inches high), between which the hot air circulated, being brought by flues from the furnace at a corner of the camp, in which it is evident that the fuel used was often the coal of Northumberland. The great number of oyster-shells, the beef-bones and mutton-bones found near many of the camps give us an indication of the food supplied to the officers, perhaps also to some of the privates. Many interesting illustrations of the immense length of time that the Roman occupation of Britain endured may be derived from these Prætenturæ. Thus we have several inscriptions recording the repair of a granary or a temple ruined by age (vetustate conlapsum): and in the sacred well of the nymph Coventina, just outside the camp of Procolitia, there were found 16,000 coins ranging over a period from A.D. 100 to 300 which had been thrown into the well by generations of Roman soldiers as votive offerings to the goddess.
Besides the larger camps, there were, as has been said, also smaller forts, erected at regular intervals of a thousand Roman paces, which are now known by the designation mile-castles; and other still smaller enclosures, hardly more than sentry boxes, about three to the mile, which are called, not very aptly, turrets, and of which very few specimens still remain.
The soldiers by whom the line of the wall was defended did not belong to the legions, though legionaries had been employed in its construction. They belonged to various auxiliary corps recruited in the outlying provinces of the empire, and they were theoretically less Roman, less Italian, than their comrades enlisted in the legions, though this distinction was practically to a large extent breaking down in the second and third centuries of the empire. While Britons were being enlisted for service abroad, Asturians from Spain, Frisians and Batavians from Holland, Tungrians from Belgium, Lingones from Gaul, even Dalmatians and Dacians from the distant provinces which bore their names, were tramping from station to station along the mighty wall of Hadrian, bathing in the chilly waters of the Tyne, or hunting the deer on the misty slopes of Cross Fell. Most gladly would we learn how these detachments of soldiers, which for something like three centuries guarded the British Limes Imperii, were recruited; whether fresh drafts came, for instance, from Spain and from Dalmatia to replace the veterans who had earned their discharge, or whether the sons of the barracks kept the barracks full, in which case there would be probably an ever-increasing strain of British blood in the limitary garrisons. But on this point we lack definite information, which may possibly be supplied to us by the spade and the pick-axe of future excavators.
The total number of actual soldiers on the line of the wall has been computed at 10,000. In addition to these there would undoubtedly be a certain number of domestic servants, grooms, camp-followers of various kinds, besides the wives and concubines of the soldiers, so that we may probably conjecture the population of the Limes at not less than 20,000, a much larger number of persons than is to be found in that beautiful but solitary region to-day. Not only the numbers but the nationality of these vanished dwellers by the Tyne and Irthing strike us by their strange contrast with the present. Besides the Asturian and Dalmatian soldiers there must have been merchants and money-lenders and camp-followers of all kinds, speaking many tongues, upon these wind-swept moorlands. In the museum at South Shields is a sepulchral monument representing a woman seated, holding in her right hand a jewel-box, in her left implements of needlework. Underneath is a bilingual inscription, telling us in Latin that the figure represents “Regina, freedwoman and wife of Barate the Palmyrene, herself of the [British] nation of the Catuallauni, who died at the age of thirty”. In characters akin to Hebrew the Oriental part of the inscription says simply, “Regina, the freedwoman of Barate. Alas!” The blended nationality, the British girl bought, enfranchised, loved and too soon lost by the Syrian,—merchant perchance or usurer,—who followed the flight of the eagles of Rome, are all brought before us by these few roughly carved lines, and they tell a story of world-wide empire, in which, perhaps, the Britain of our own day could offer the closest parallel to Rome.
Under the Emperor Antoninus Pius (138–161), the successor of Hadrian, another wall was built, some fifty or sixty miles north of the first, between the Firths of Forth and of Clyde. There were no stones in this wall, which was made of layers of turf, and, moreover, it has suffered cruelly (from an archæological point of view) through the operations necessary first for the cutting of a canal and afterwards for the building of a railroad between the two seas; but an abundance of inscribed stones tell us much concerning the names and occupations of the soldiers by whom it was garrisoned, and abundantly confirm the testimony of historians who attribute its erection to Antoninus Pius (138–161), one of the best and noblest of Roman emperors. Doubtless, at the time of its building, the country between the two walls (comprising the county of Northumberland and the whole south of Scotland) was subject to Roman rule. The precise period when that district was finally lost to the empire is still unknown to us. The philosopher emperor, Marcus Aurelius (161–180), was closely occupied with the defence of the empire against the barbarians of the Middle Danube, and his name is scarcely mentioned in connexion with the history of Britain. We are told, however, that “the Britannic war pressed heavily on his mind,” and that he sent a second Agricola to settle it. This general of Marcus, Calpurnius Agricola, was not, as far as we know, descended from his great namesake, the general of Domitian.
With the accession of Commodus (180–192), son of Marcus, the long and glorious period of the patriot emperors came to an end, and the ruin of the empire began. The foolish and headstrong boy, who was now lord of the Roman world, sacrificed some of the best generals in his service to his jealous and cowardly suspicions, and while he was devoting himself to the bloody pastimes of the amphitheatre, allowed the necessary work of the defence of the frontier to fall behind. “The tribes in the island of Britain,” we are told by Dion Cassius, “over-passed the wall which separated them from the Roman armies, committed widespread ravages, and cut to pieces a Roman general with the troops under his command.” Which of the two walls is here referred to is not easy to say. It may be conjectured, however, that the wall of Antoninus had been already broken down in the reign of Marcus, during the “heavily pressing” Britannic war, and that we have here a description of one of those barbaric demolitions of which we find such abundant traces in the wall of Hadrian. To chastise the barbarians and to restore the broken Limes Commodus sent probably his best general, the sturdy old soldier, Ulpius Marcellus. If discipline were relaxed in the legions on the British frontier, here was certainly the man to restore it. St. Paul himself was not more resolute to “buffet his body and bring it into subjection” than this chief of many legions. A scanty sleeper himself, he framed ingenious plans to keep his centurions and officers at night harassed and awake. An old man with toothless and tender gums, he would eat only the stale hard bread which he had brought from Rome, in order that he might not fall into gluttony and excess. Such was the man who restored for a time the honour of the Roman arms, and who chastised the barbarians so thoroughly that all men marvelled that he was not, on his return to Rome, condemned to death by the jealous Commodus.
The assassination of Commodus (192), followed in less than three months by the murder of his excellent successor, Pertinax, and by the sale of the imperial dignity to the highest bidder, introduced a dreadful period of civil war in which the whole empire had nearly fallen asunder in ruin. Of the three candidates for the purple, Pescennius Niger in Syria, Albinus in Britain, and Septimius Severus on the Middle Danube, Severus, who had the advantage of being nearest to the capital and was therefore first acclaimed as emperor, was also at last the victorious one, but he had a hard fight, especially with Albinus, who led the three legions which still composed the army of Britain to a bloody battle in the plains of Lyons. The confusion of the times and the absence of the Roman legions were undoubtedly favourable to the restless barbarians. The wall of Hadrian was broken through; the Mæatæ, who lived immediately to the north of it, burst into the province, and the governor, Virius Lupus, purchased a precarious peace by paying a large sum to the invaders. It may be easily imagined that the condition of Britain after such an ignominious conclusion of a campaign, and even after the return of the disaffected legions of Albinus, was far from satisfactory, but it was apparently not till 208 that Septimius Severus set forth from Rome to bring the affairs of the province into order. He was already more than sixty years of age, his joints were racked by gout and his heart was sore through the fierce dissensions of his two sons, Caracalla and Geta, and the evils which these foreboded for the empire. Yet even these dissensions urged him the more to undertake the expedition, for he hoped that common labours and common dangers might in some degree tend to draw the two hostile brothers together, and that the necessary hardships of a camp life under our northern skies might restore some of the moral tone which had been lost amid the vicious indulgences of Rome. In this hope, it is true, he was completely disappointed. The hatred of Caracalla, especially for his brother, waxed fiercer and fiercer, and included also his father, for whose death he longed with scarcely concealed eagerness. Borne in his litter, on account of his sufferings from gout, the brave old soldier traversed the greater part of Caledonia, hewing down forests and throwing causeways across marshes; slaying, of course, multitudes of barbarians, but losing also 50,000 of his own troops (so we are told, but the estimate is probably exaggerated) by hostile ambuscades, severities of weather, even by the swords of his own soldiers, who often killed their own comrades to prevent their falling into the hands of the barbarians. He had a mind, too, to explore the secrets of Nature, and compared with wonder the all-but perpetual day of midsummer and the scanty measure of light at midwinter in northern Scotland.
The dates of Severus’ campaign are only obscurely indicated, but it seems probable that by the year 210 the subjection of the Caledonians had been apparently completed. Severus, accompanied by Caracalla and his staff, was riding on horseback, notwithstanding his physical infirmity, towards a certain place of meeting which had been appointed for the barbarians, that they might surrender their swords and swear fidelity to the empire. Caracalla, riding behind him, drew his sword and made his horse rear and prance, intending, apparently, to be brought into collision with his father and thus to kill him by apparent misadventure. A warning shout from some member of the staff caused the emperor to look round and the parricidal design was foiled. Severus said nothing, but rode calmly on, took his place on the tribunal and went through the ceremony that had been arranged. He then sent for his son and two of his chief ministers (one of them the great lawyer Papinian), having ordered that a naked sword should be placed in the middle of the tent. He sternly rebuked his son for the impious deed which he had meditated in the sight of the allies and the enemies of Rome, and then, changing his tone, said: “If you still desire to slay me, here is the sword, draw it and destroy me. Or, since I have associated you with me in the empire, give your orders to Papinian and let him be my executioner. You are young and strong: I am old and shall lay me down to rest without a sigh.” The invitation was not accepted, for Caracalla shrank now from the guilt of manifest parricide. But the father’s words revealed too plainly the bitterness of his soul. Many cruelties and much needless bloodshed had marked his own ascent to power, but they were surely all avenged by the misery of that day in the land of the Caledonians.