This great commander formed a regular plan for subduing Britain, and rendering the acquisition useful to the conquerors. He carried his victorious arms northwards, defeated the Britons in every encounter, pierced into the inaccessible forests and mountains of Caledonia, reduced every state to subjection in the southern parts of the island, and chaced before him all the men of fiercer and more intractable spirits, who deemed war and death itself less intolerable than servitude under the victors. He even defeated them in a decisive action, which they sought under Galgacus, their leader; and having fixed a chain of garrisons, between the friths of Clyde and Forth, he thereby cut off the ruder and more barren parts of the island, and secured the Roman province from the incursions of the barbarous inhabitants.n
During these military enterprizes, he neglected not the arts of peace. He introduced laws and civility among the Britons, taught them to desire and raise all the conveniencies of life, reconciled them to the Roman language and manners, instructed them in letters and science, and employed every expedient to render those chains, which he had forged, both easy and agreeable to them.o The inhabitants, having experienced how unequal their own force was to resist that of the Romans, acquiesced in the dominion of their masters, and were gradually incorporated as a part of that mighty empire.
This was the last durable conquest made by the Romans; and Britain, once subdued, gave no farther inquietude to the victor. Caledonia alone, defended by barren mountains, and by the contempt which the Romans entertained for it, sometimes infested the more cultivated parts of the island by the incursions of its inhabitants. The better to secure the frontiers of the empire, Adrian, who visited this island, built a rampart between the river Tyne and the frith of Solway: Lollius Urbicus, under Antoninus Pius, erected one in the place where Agricola had formerly established his garrisons: Severus, who made an expedition into Britain, and carried his arms to the most northern extremity of it, added new fortifications to the wall of Adrian; and during the reign of all the Roman emperors, such a profound tranquillity prevailed in Britain, that little mention is made of the affairs of that island by any historian. The only incidents, which occur, are some seditions or rebellions of the Roman legions quartered there, and some usurpations of the imperial dignity by the Roman governors. The natives, disarmed, dispirited, and submissive, had left all desire and even idea of their former liberty and independence.
But the period was now come, when that enormous fabric of the Roman empire, which had diffused slavery and oppression, together with peace and civility, over so considerable a part of the globe, was approaching towards its final dissolution. Italy, and the center of the empire, removed, during so many ages, from all concern in the wars, had entirely lost the military spirit, and were peopled by an enervated race, equally disposed to submit to a foreign yoke, or to the tyranny of their own rulers. The emperors found themselves obliged to recruit their legions from the frontier provinces, where the genius of war, though languishing, was not totally extinct; and these mercenary forces, careless of laws and civil institutions, established a military government, no less dangerous to the sovereign than to the people. The farther progress of the same disorders introduced the bordering barbarians into the service of the Romans; and those fierce nations, having now added discipline to their native bravery, could no longer be restrained by the impotent policy of the emperors, who were accustomed to employ one in the destruction of the others. Sensible of their own force, and allured by the prospect of so rich a prize, the northern barbarians, in the reign of Arcadius and Honorius, assailed at once all the frontiers of the Roman empire; and having first satiated their avidity by plunder, began to think of fixing a settlement in the wasted provinces. The more distant barbarians, who occupied the deserted habitations of the former, advanced in their acquisitions, and pressed with their incumbent weight the Roman state, already unequal to the load which it sustained. Instead of arming the people in their own defence, the emperors recalled all the distant legions, in whom alone they could repose confidence; and collected the whole military force for the defence of the capital and center of the empire. The necessity of self-preservation had superseded the ambition of power; and the ancient point of honour, never to contract the limits of the empire, could no longer be attended to in this desperate extremity.
Britain by its situation was removed from the fury of these barbarous incursions; and being also a remote province, not much valued by the Romans, the legions, which defended it, were carried over to the protection of Italy and Gaul. But that province, though secured by the sea against the inroads of the greater tribes of barbarians, found enemies on its frontiers, who took advantage of its present defenceless situation. The Picts and Scots, who dwelt in the northern parts, beyond the wall of Antoninus, made incursions upon their peaceable and effeminate neighbours; and besides the temporary depredations which they committed, these combined nations threatened the whole province with subjection, or, what the inhabitants more dreaded, with plunder and devastation. The Picts seem to have been a tribe of the native British race, who, having been chaced into the northern parts by the conquests of Agricola, had there intermingled with the ancient inhabitants: The Scots were derived from the same Celtic origin, had first been established in Ireland, had migrated to the north-west coasts of this island, and had long been accustomed, as well from their old as their new feats, to infest the Roman province by pyracy and rapine.NOTE [A] These tribes, finding their more opulent neighbours exposed to invasion, soon broke over the Roman wall, no longer defended by the Roman arms; and though a contemptible enemy in themselves, met with no resistance from the unwarlike inhabitants. The Britons, accustomed to have recourse to the emperors for defence as well as government, made supplications to Rome; and one legion was sent over for their protection. This force was an over-match for the barbarians, repelled their invasion, routed them in every engagement, and having chaced them into their ancient limits, returned in triumph to the defence of the southern provinces of the empire.p Their retreat brought on a new invasion of the enemy. The Britons made again an application to Rome, and again obtained the assistance of a legion, which proved effectual for their relief: But the Romans, reduced to extremities at home, and fatigued with those distant expeditions, informed the Britons that they must no longer look to them for succour, exhorted them to arm in their own defence, and urged, that, as they were now their own masters, it became them to protect by their valour that independence, which their ancient lords had conferred upon them.q That they might leave the island with the better grace, the Romans assisted them in erecting anew the wall of Severus, which was built entirely of stone, and which the Britons had not at that time artificers skillful enough to repair.r And having done this last good office to the inhabitants, they bid a final adieu to Britain, about the year 448; after being masters of the more considerable part of it during the course of near four centuries.
THE BRITONS
THE ABJECT BRITONS regarded this present of liberty as fatal to them; and were in no condition to put in practice the prudent counsel given them by the Romans, to arm in their own defence. Unaccustomed both to the perils of war, and to the cares of civil government, they found themselves incapable of forming or executing any measures for resisting the incursions of the barbarians. Gratian also and Constantine, two Romans who had a little before assumed the purple in Britain, had carried over to the continent the flower of the British youth; and having perished in their unsuccessful attempts on the imperial throne, had despoiled the island of those, who, in this desperate extremity, were best able to defend it. The Picts and Scots, finding that the Romans had finally relinquished Britain, now regarded the whole as their prey, and attacked the northern wall with redoubled forces. The Britons, already subdued by their own fears, found the ramparts but a weak defence for them; and deserting their station, left the country entirely open to the inroads of the barbarous enemy. The invaders carried devastation and ruin along with them; and exerted