Picts, Saxons, Scots Irish and Attecotti combined to raid Britain in the “Barbarian Conspiracy” of 365 to 368. Attecotti were especially savage and dreaded raiders and mercenaries, who St. Jerome wrote in 393 he had seen in his youth (probably in Gaul 365-370) indulging in canibalis “prefering the haunch of the shepherd to his sheep”, and who emigrated from Northern Ireland to Caithness, Man and the Hebrides. Sufficient Attecotti were captured by the Romans for 4 auxilia palatina to be recruited from them in the reign of Honorius (392 – 423). Insufficient is known to justify a separate list for Attecotti. They are not heard of after 406. Pictish raids on Roman Britain often outflanked Hadrian’s Wall by sea and the power of the Pictish fleet is mentioned with awe in the Irish annals of Tigernach. Whether their vessels were leather-covered curraghs like those of the Scots-Irish, or plank built, is disputed.
In 360, the Scotti and Picti broke an existing treaty between themselves and the Roman authorities; they then mounted major attacks on Britain. Irish participation indicates an ability to move men across the sea in large numbers; this is most easily explained if they had had the major share in the trade likely to have occurred under the terms of the treaty broken in 360. In 364, Britain continued to suffer from attacks by Picts, Saxons, Attacotti, and Scotti. In 367, there occurred what was believed by the Romans to be a `great conspiracy’ between the Scotti, Attacotti, Picti, and Saxones, as well as Franks, leading to a major combined attack on Roman Britain and the northern coastlands of Gaul. The primary target of the Saxons and Franks was apparently Gaul rather than Britain. The Scotti, Attacotti, and Picti were able to defeat and demoralize the Roman army in Britain to such an extent that they could devote themselves to plundering the country. Some cities must have suffered, since they are said by Ammianus to have been restored by Count Theodosius. When this Theodosius (father of the later emperor) was sent by the Emperor Valentinian to recover Britain, he established his base at Richborough, and was followed by four detachments of the field army, Batavians, Heruli, Iovii, and Victores. He then made for London, encountering detachments of the enemy, burdened by plunder, on his way. The invaders, therefore, had been able to plunder even the far south-east. After he had entered London to the huge relief of the citizens, Count Theodosius was able to entice back many of those who had deserted from the Roman army in Britain in the face of barbarian invasion and victory. With these reinforcements and his four elite detachments from the field army, he was able to clear the British provinces of the barbarians and restore the Roman order.
A striking feature of Ammianus’s contemporary account is that Theodosius was confronted almost as much by disloyalty within the former army of Britain as he was by barbarians. The invasion of 367 seems to have begun with the treachery of the frontier scouts, whose responsibility it was to monitor the peoples north of the Wall from advance forts at Bewcastle in the west and Risingham in the east. Their treachery was then imitated by others in the army to the south.
The British peoples between Hadrian’s Wall and the Forth are not mentioned as such in Ammianus’s narrative, yet the implication of what he says about the frontier scouts, the arcani or areani, would appear to be that the Britons beyond Hadrian’s Wall had joined, or been compelled to join, the great barbarian conspiracy. Although Ammianus portrays Theodosius’s achievement as a general restoration of the Roman defences and administration, it is doubtful whether the forts north of the Wall were reoccupied after 367. And it is certain that he abolished the frontier scouts, whose treachery had facilitated the barbarian invaders. Yet, even though the northern Britons were probably part of the `barbarian conspiracy’, they were not, in the long run, assimilated into the Pictish confederation. Why this was so, is not easy to explain. After all, the Picts originated as a confederation of British peoples beyond the reach of Rome, so that one might imagine that any British people beyond Hadrian’s Wall that shared in a major Pictish attack on Roman Britain would be likely to be brought into the Pictish federation itself. There may, therefore, have been a contrast between a short-term participation in the great attack of 367 and a quite different and more long-term policy in normal times. What was happening in northern Britain in the late fourth century cannot be understood without taking the long term into account.
So far as we can tell, the peoples north of the Forth were regarded in the first and second centuries as Britons; the leading people among them, according to Tacitus’s Life of his father-in-law Agricola, was called the Caledonii (Welsh Celyddon); others mentioned elsewhere included the Verturiones and the Maeatae. Because of the predominance of the Caledonii, Tacitus used the term Caledonia for the land Agricola was attempting to conquer beyond the Forth and Clyde, and even speaks of `the peoples inhabiting Caledonia’. From the Renaissance, therefore, it was only natural to adopt Caledonia as a Latin name for Scotland. Yet any temptation to assume a distinction between Britons and Caledonians in Antiquity should be resisted: for Tacitus, the Caledonians were Britons. By the eighth century, however, the Picts were, for Bede, a distinct people with their own language-distinct both from the Britons to the south and from the Irish; and there is no reason to think that his perception was in any way idiosyncratic. Yet, if the particular ways in which the Pictish language became distinct from British are examined, all of them can be dated later than the emergence of Picts in the written sources at the end of the third century. The linguistic distinctiveness of the Picts, accepted without question by Bede, was, by the eighth century, real; but it appears to have been a consequence, not a precondition, of the Pictish confederation. Picts came first, Pictish only subsequently. The internal composition of the federations opposing Roman power in the north varied from one occasion to another. In the reign of Severus, the Maeatae, supported by Caledonii, opposed Roman power in the north. According to Ammianus, the Picts were divided into two peoples, the Dicalydones and the Verturiones. The latter gave the early medieval name for a territory, Fortriu, and strong arguments have been put forward for placing this north of the Mounth. Throughout the late-Roman and post-Roman periods, therefore, the Picts remained a federation of peoples.
As we have seen, such federations of smaller peoples emerged in the late Empire on the Rhine frontier: the Franks on the lower Rhine and the Alamans on the upper Rhine. The Pictish federation is likely to be another such political effect of the Roman frontier: as the Franks emerged opposite Lower Germany and the Alamans opposite Upper Germany, so the Picts appear to have been the federation that emerged opposite the northern frontier of Britain. Yet, if this is the case, the effective frontier in this context was not Hadrian’s Wall. In the end, it was not even precisely the Antonine Wall, but further north, especially in the west, where the main British centre of power in the post-Roman period was Alclud, Dumbarton Rock, on the north side of the Clyde and also to the north of the Antonine Wall. The boundary between Pict and Briton lay along the northern frontiers of peoples, the Votadini in the east and the Dumnonii in the west, not any Roman fortified limes. It is difficult to see how this could have happened unless those northern peoples that remained British had been Roman clients on an enduring basis. On the other hand, those peoples that were brought into the Pictish federation would either not have been Roman clients at all or clients only for a short period.
Whether this system of clientship was restored after the crisis of 367 has been debated. According to one view, the finds from the excavation of Traprain Law in Votadinian territory included plenty of ordinary Roman material from an earlier period, but after 367 only what was interpreted as `a great treasure of stolen Roman plate’. More recently, however, it has been argued that some of this bullion, at least, corresponds to Roman weights and might, therefore, have been a gift or gifts to clients or allies. A parallel from the fifth century may be helpful here. During St Patrick’s episcopate in Ireland, the soldiers of a British king called Coroticus allied themselves with Picts and Irish in order to carry out a raid within Ireland. The raid was successful in carrying off slaves, including some who had only recently been baptized. In response, Patrick wrote an open letter addressed to these soldiers. He did not say what territory Coroticus ruled, but a list of contents in the Book of Armagh identified him as king of Ail Cluaithe, namely Alclud. The alliance with Picts in a raid on Irish territory makes this very plausible, and the name Ceredig appears in the pedigree of the kings of Alclud. If this is correct, what is striking is the way Patrick denounced the king’s soldiers: `I do not describe them as my citizens nor as citizens of Roman Christians, but as citizens of the demons.’ These words would have no point unless the soldiers of Coroticus would have considered themselves to be Patrick’s fellow-citizens and citizens of the Romans. The date at which this letter was written is probably in the second half of the fifth century, approximately a century after `the barbarian conspiracy’ of 367 and long after the Roman army had been withdrawn from Britain. What it shows, provided Coroticus is correctly identified, is that a British king could ally with Picts and Scotti to mount a raiding expedition on Ireland of much the same kind as those that devastated Roman Britain a century earlier, and that he could be denounced on these grounds for flouting the obligations of a `citizen’. The geographical limit of `the citizens’ would appear now to be identical with the limit of British territory. This could hardly have happened unless the kind of alliance of northern Britons with Picts and Scotti that apparently took place in the 360s, and again with Coroticus, had been exceptional. Otherwise the major divide would have come to be on the Tyne-Solway line, not on the Forth and the watershed on the north side of the Clyde basin.
Any ethnic distinction, then, between Pict and Briton was only slowly emerging in the late Roman period. The division between those who were part of the Pictish federation and the Britons was not initially ethnic but a political and cultural division between a normal adhesion to Rome and normal independence. The northern Britons’ adhesion to Rome was not just a matter of clientship, but extended into broader aspects of culture. The Britons adopted the habit of putting up inscriptions from Rome; they accepted Christianity earlier and more readily than did the Picts. Part of the significance of 367, therefore, lay in an abnormality: the northern Britons, on this occasion, would appear to have combined their forces with those of the Picts, the Scotti, and the Attacotti, whereas, normally, they sided with Rome. The significance of Patrick’s encounter with Coroticus is the same. The king’s alliance with Picts and Scotti is treated as an aberration, showing that the normal allegiance endured long after the Roman army had been withdrawn.