A.D. 287.
Revolt of Carausius; Britain for ten years independent.
There occurs again at this period a silence as to the relative position of the Romans and the barbarian tribes, till, after an interval of seventy-five years, the attention of the Roman historians is once more called to this distant part of the Empire by the revolt and usurpation of the purple by Carausius, in the early part of the reign of the Emperor Diocletian. In accordance with a custom now becoming frequent in the Roman Empire, Diocletian had associated with him in the government Maximian, and to the share of the latter fell the western provinces of Gaul, Spain, and Britain. A new feature now took place in the history of these provinces. This was the appearance of two new barbaric nations, destined to occupy an important position among the European kingdoms—the Franks and the Saxons—who now appeared in the British seas and ravaged the coasts of Gaul, Belgium, and Britain. In order to repress them and to protect these countries from their inroads, a Roman fleet was stationed at Gesoriacum or Boulogne. Carausius, a native of the city of Menapia in Belgium, who had risen to eminence in the Roman army, was appointed to command it, and soon distinguished himself in repressing the inroads of these new barbarian tribes. He was accused, however, of retaining the spoil he took from them, which he ought to have accounted for, and of encouraging them in their piratical expeditions in order that he might secure for himself the booty they had taken. Maximian, in consequence, resolved to put him to death; but Carausius, having become aware of his intention, anticipated the resolution of the Emperor by assuming the purple and taking possession of the provinces of Britain. He took with him in his revolt the fleet under his charge; the Roman soldiers in Britain obeyed him, and he increased his naval force by building numerous new vessels.[[82]]
A.D. 289. Carausius admitted Emperor.
A Barbarian by birth, and consequently connected with native tribes, he appears to have received the ready submission of the Britons, as well as the support of the independent tribes, and Britain for the time assumed the appearance of a separate empire, in which he maintained himself by his fleet. Maximian, after trying in vain to reduce him, at length concluded a peace, bestowing upon him the title of Augustus, and intrusting to him the care of those provinces he had already taken possession of.[[83]] In the meantime, owing to the disturbed state of the Empire and the revolt in Britain, Diocletian created Galerius Maximian and Constantius Chlorus, Cæsars.
A.D. 29 Constantius Chlorus recovers Britain.
It appears that the latter, to whose share the provinces of Gaul, Spain, and Britain were assigned, resolved to wrest the provinces of Britain from the usurper, but of the particulars of this war we know nothing except what may be gathered from a few hints of the panegyrists. We ascertain from them that in the year 292 Constantius Chlorus had wrested Gaul from the influence of Carausius, and besieged and taken possession of the harbour of Boulogne, compelling Carausius to withdraw his ships to Britain, where his rule was popular, Constantius being unable to carry the war into Britain for want of vessels.[[84]]
A.D. 294.
Carausius slain by Allectus.
The reign of Carausius was one of prosperity to the Britons, and his government vigorous, but it was terminated by his assassination by Allectus, one of his followers, who had conspired against him, and whose cause seems to have been mainly supported by the independent tribes. Allectus had not been long in the enjoyment of his insular dominion, when Constantius Chlorus, having now caused vessels to be made, sailed from Boulogne to Britain two years after the death of Carausius. He is described as passing in a mist the British fleet which was cruising near the Isle of Wight, and landed in Britain, when he marched upon London, and his army under Asclepiodotus, having followed Allectus, a battle took place in which the latter was defeated and slain. It was found after the battle that Allectus had few Roman soldiers, and that his army consisted principally of Barbarians who had been enlisted by him, and in whom, from the allusion by the panegyrists to a marked characteristic indicated by Tacitus as distinguishing them from the rest of the Britons, we can recognise the inhabitants of Caledonia.[[85]] Britain had thus been separated from the rest of the Roman Empire for ten years, seven of which belong to the reign of Carausius, and three to that of Allectus, and had for the greater part of that time been under the government of one who united an origin derived from the native tribes with the imperial authority. It almost seemed as if she was destined at that early period to commence her independent existence as a great maritime power, had the assassination of Carausius not altered the character of her fortunes.
A.D. 306. War of Constantius Chlorus against Caledonians and other Picts.
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.