The termination of this independent government was the signal for the independent tribes to break out into hostilities; and, as they emerged from under the government of Carausius and Allectus into their old position towards the Roman province they now appear for the first time under the general name of Picts, one section of whom bore the name of Caledones. On the abdication of Diocletian in 305, Constantius Chlorus became Emperor of the West, and apparently made Britain his residence during the greater part of his short reign. In its first year he appears to have penetrated beyond the wall, entered the plains of the low country north of it, and defeated the Picts, who are said by one of the panegyrists to have consisted of the Caledones and other nations not named, but in whom we can well recognise those termed by Dio the Mæatæ.[86] This expedition was probably limited to the territory beyond the wall which had been ceded to the Romans in the peace concluded with the Emperor Severus. In the following year Constantius died at York, and his son Constantine, having become Emperor, left Britain to take possession of the Empire. We now hear little of Britain, and nothing of the nations beyond the boundary of the Roman province, for a period of fifty years, till in the year 360 a new and very important feature in the history of the Roman occupation of Britain manifested itself. This was the commencement of those formidable and systematic inroads of the Barbarian tribes into the province, which were not merely temporary expeditions for plunder, but evidently aimed at the subversion of the Roman government in Britain, and, though checked at intervals, were ever again renewed till the Romans finally abandoned the possession of the island. From the expedition of Severus to the commencement of these formidable attacks a period of 150 years had elapsed, and the few notices we have of the events in Britain show that the integrity of the province had on the whole been maintained, and that the provincial Britons enjoyed some degree of security within its bounds, while the northern tribes were restrained from making incursions beyond their territory by the well-guarded wall, which with its numerous posts along its line, and, in advance of it, in the ceded district, protected the frontier. The ten years’ independent kingdom under Carausius and Allectus had not affected this state of matters. The provincial Britons must have been equally protected, especially under the vigorous government of the former. There are even indications of its influence having extended over the independent tribes, and bodies of them, whom Allectus had enlisted, were found in his army. On the termination of this independent empire, they emerge under a new name; and their defeat and expulsion from the province was a necessary consequence of the renewed union of Britain with the continental provinces under the same authority.