Bede's Ecclesiastical History of England, ed. by A.M. Sellar, , at sacred-texts.com
FROM that time, the British part of Britain, destitute of armed soldiers, of all military stores, and of the whole flower of its active youth, who had been led away by the rashness of the tyrants never to return, was wholly exposed to rapine, the people being altogether ignorant of the use of weapons. Whereupon they suffered many years from the sudden invasions of two very savage nations from beyond the sea, the Scots from the west, and the Picts from the north. We call these nations from beyond the sea, not on account of their being seated out of Britain, but because they were separated from that part of it which was possessed by the Britons, two broad and long inlets of the sea lying between them, one of which runs into the interior of Britain, from the Eastern Sea, and the other from the Western, though they do not reach so far as to touch one another. The eastern has in the midst of it the city Giudi. On the Western Sea, that is, on its right shore, stands the city of Alcluith, which in their language signifies the Rock Cluith, for it is close by the river of that name.
On account of the attacks of these nations, the Britons sent messengers to Rome with letters piteously praying for succour, and promising perpetual subjection, provided that the impending enemy should be driven away. An armed legion was immediately sent them, which, arriving in the island, and engaging the enemy, slew a great multitude of them, drove the rest out of the territories of their allies, and having in the meanwhile delivered them from their worst distress, advised them to build a wall between the two seas across the island, that it might secure them by keeping off the enemy. So they returned home with great triumph. But the islanders building the wall which they had been told to raise, not of stone, since they had no workmen capable of such a work, but of sods, made it of no use. Nevertheless, they carried it for many miles between the two bays or inlets of the sea of which we have spoken; to the end that where the protection of the water was wanting, they might use the rampart to defend their borders from the irruptions of the enemies. Of the work there erected, that is, of a rampart of great breadth and height, there are evident remains to be seen at this day. It begins at about two miles distance from the monastery of Aebbercurnig, west of it, at a place called in the Pictish language Peanfahel, but in the English tongue, Penneltun, and running westward, ends near the city of Aicluith.
But the former enemies, when they perceived that the Roman soldiers were gone, immediately coming by sea, broke into the borders, trampled and overran all places, and like men mowing ripe corn, bore down all before them. Hereupon messengers were again sent to Rome miserably imploring aid, lest their wretched country should be utterly blotted out, and the name of a Roman province, so long renowned among them, overthrown by the cruelties of foreign races, might become utterly contemptible. A legion was accordingly sent again, and, arriving unexpectedly in autumn, made great slaughter of the enemy, obliging all those that could escape, to flee beyond the sea; whereas before, they were wont yearly to carry off their booty without any opposition. Then the Romans declared to the Britons, that they could not for the future undertake such troublesome expeditions for their sake, and advised them rather to take up arms and make an effort to engage their enemies, who could not prove too powerful for them, unless they themselves were enervated by cowardice. Moreover, thinking that it might be some help to the allies, whom they were forced to abandon, they constructed a strong stone wall from sea to sea, in a straight line between the towns that had been there built for fear of the enemy, where Severus also had formerly built a rampart. This famous wall, which is still to be seen, was raised at public and private expense, the Britons also lending their assistance. It is eight feet in breadth, and twelve in height, in a straight line from east to west, as is still evident to beholders. This being presently finished, they gave the dispirited people good advice, and showed them how to furnish themselves with arms. Besides, they built towers to command a view of the sea, at intervals, on the southern coast, where their ships lay, because there also the invasions of the barbarians were apprehended, and so took leave of their allies, never to return again.
After their departure to their own country, the Scots and Picts, understanding that they had refused to return, at once came back, and growing more confident than they had been before, occupied all the northern and farthest part of the island, driving out the natives, as far as the wall. Hereupon a timorous guard was placed upon the fortification, where, dazed with fear, they became ever more dispirited day by day. On the other side, the enemy constantly attacked them with barbed
weapons, by which the cowardly defenders were dragged in piteous fashion from the wall, and dashed against the ground. At last, the Britons, forsaking their cities and wall, took to flight and were scattered. The enemy pursued, and forthwith followed a massacre more grievous than ever before; for the wretched natives were torn in pieces by their enemies, as lambs arc torn by wild beasts. Thus, being expelled from their dwellings and lands, they saved themselves from the immediate danger of
starvation by robbing and plundering one another, adding to the calamities inflicted by the enemy their own domestic broils, till the whole country was left destitute of food except such as could be procured in the chase.