History Of The Britons (Historia Brittonum) by Nennius
23. Severus was the third emperor who passed the sea to Britain, where, to protect the provinces recovered from barbaric incursions, he ordered a wall and a rampart to be made between the Britons, the Scots, and the Picts, extending across the island from sea to sea, in length one hundred and thirty-three miles: and it is called in the British language Gwal.* Moreover, he ordered it to be made between the Britons, and the Picts and Scots; for the Scots from the west, and the Picts from the north, unanimously made war against the Britons; but were at peace among themselves. Not long after Severus dies in Britain.
*Or, the Wall. One MS. here adds, "The above-mentioned Severus constructed it of rude workmanship in length 132 miles; i.e. from Penguaul, which village is called in Scottish Cenail, in English Peneltun, to the mouth of the river Cluth and Cairpentaloch, where this wall terminates; but it was of no avail. The emperor Carausius afterwards rebuilt it, and fortified it with seven castles between the two mouths: he built also a round house of polished stones on the banks of the river Carun [Carron]: he likewise erected a triumphal arch, on which he inscribed his own name in memory of his victory.
24. The fourth was the emperor and tyrant, Carausius, who, incensed at the murder of Severus, passed into Britain, and attended by the leaders of the Roman people, severely avenged upon the chiefs and rulers of the Britons, the cause of Severus.*
* This passage is corrupt, the meaning is briefly given in the translation.
25. The fifth was Constantius the father of Constantine the Great. He died in Britain; his sepulchre, as it appears by the inscription on his tomb, is still seen near the city named Cair segont (near Carnarvon). Upon the pavement of the above-mentioned city he sowed three seeds of gold, silver and brass, that no poor person might ever be found in it. It is also called Minmanton.*
* V.R. Mirmantum, Mirmantun, Minmanto, Minimantone. The Segontium of Antoninus, situated on a small river named Seiont, near Carnarvon.
26. Maximianus was the sixth emperor that ruled in Britain. It was in his time that consuls began, and that the appellation of Caesar was discontinued: at this period also, St. Martin became celebrated for his virtues and miracles, and held a conversation with him.
 This is an inaccuracy of Nennius; Maximus and Maximianus were one and the same person; or rather no such person as Maximianus ever reigned in Britain.
 Geoffrey of Monmouth gives the title of consul to several British generals who lived after this time. It is not unlikely that the town, name, and dignity, still lingered in the provinces after the Romans were gone, particularly as the cities of Britain maintained for a time a species of independence.
27. The seventh emperor was Maximus. He withdrew from Britain with all his military force, slew Gratian, the king of the Romans, and obtained the sovereignty of all Europe. Unwilling to send back his warlike companions to their wives, children, and possessions in Britain, he conferred upon them numerous districts from the lake on the summit of Mons Jovis, to the city called Cant Guic, and to the western Tumulus, that is, to Cruc Occident.* These are the Armoric Britons, and they remain there to the present day. In consequence of their absence, Britain being overcome by foreign nations, the lawful heirs were cast out, till God interposed with his assistance. We are informed by the tradition of our ancestors that seven emperors went into Britain, though the Romans affirm there were nine.
* This district, in modern language, extended from the great St. Bernard in Piedmont to Cantavic in Picardy, and from Picardy to the western coast of France.
28. Thus, aggreeably to the account given by the Britons, the Romans governed them four hundred and nine years.
After this, the Britons despised the authority of the Romans, equally refusing to pay them tribute, or to receive their kings; nor durst the Romans any longer attempt the government of a country, the natives of which massacred their deputies.
By Dr Miles RussellThe chapters in this volume, each written by a leading scholar of the period, analyse in turn the different nationalities and kingdoms that existed in the British Isles from the end of the Roman empire to the coming of the Vikings, the process of conversion to Christianity, the development of art and of a written culture, and the interaction between this written culture and the societies of the day. Available from: