Or a brief summary of the historical events that followed the demise of Roman Britain. Sub-Roman Britain being the technical term bestowed on that period in British history from
the point at which the Roman historical record ends in 409 AD to the point at which the Anglo-Saxon historical record begins, which is roughly speaking the arrival of Augustine in 597 AD to convert the pagan Anglo-Saxons to Christianity.
Throughout the fourth century the Western Roman Empire came under increasing pressure from the Germanic barbarian tribes on its eastern borders. Gaul suffered the most from repeated incursions but Britain endured its share of discomfort with serious raids in 360, 367, 382 and 405 AD inflicted by various tribes of Scots, Picts and GermanicSaxons.
This led to a loss of confidence in the western emperors, which encouraged the Roman army in Britain to elevate a succession of usurpers to the imperial throne; first Magnus Maximus in 383, then Marcus and Gratian in 406 and finally Constantine III in 407. Neither Marcus nor Gratian lasted very long, (both where killed within months of their appointment), but both Magnus Maximus and Constantine III led their armies across the channel and followed a pattern of briefly ruling a northern empire based on Britain, Gaul and Iberia, before their ultimate defeat and death.
Whereas we cannot say for certain what troops were permanently withdrawn by Magnus Maximus and Constantine III, or indeed by the Roman general Stilicho in 402, we can reasonably conclude that the military establishment in Britannia had been denuded to a considerable extent.
Finally frustration at the regime of Constantine III and his inability to provide an adequate protection against the Anglo-Saxon raids of 408 led to the Romano-British Revolt of 409, when the Romano-British made a bid for independence from Rome. Whether the Honarian rescript of 410 actually occurred or not, it is clear that it was at this point that Roman Britain became detached from the Empire.
An independent Romano-Britain
At which point in time we fall into the abyss of what is technically called Sub-Roman Britain. It is only with the greatest difficulty that any kind of coherent narrative can be put together and such is the paucity of information that almost the only historically verifiable event is that of the visit of Germanus of Auxerre in 429 AD.
The narrative that follows therefore is as speculative as it is historical.
The decades following the revolt appear to have been relatively peaceful (as far as we know). In the political vacuum created by the break with the Empire all sorts of warlords and strong-arm men made their bid for glory. One of these was Vortigern, who came to the forefront around 425 AD and sought to establish an independent Romano-British kingdom.
He appears to have been opposed by Ambrosius Aurelianus and central to Vortigern's policy was the use of Germanic mercenary troops or foederati to defend both the nation from external raiders and Vortigern himself against his domestic enemies.
What exact date we can place on the arrival of the Saxons is uncertain, but we can be certain that they did and that sometime between 429 and 441 these Germanic or Saxon foederati rebelled and led to the War of the Saxon federates, a conflict that appears to have resulted in the downfall of Vortigern. A conflict that also seems to have led to a much wider struggle for Britain itself which lasted for most of the latter half of the fifth century.
At one point the evidence of the Gallic Chronicles as well as the lamentations of the Britons suggests that the Anglo-Saxon invaders were on the brink of conquering the entire island. Britain, it seemed was about to enjoy the same fate as the rest of western Europe, and fall under the dominion of the Germanic insurgents.
But Vortigern's fall led to his replacement by Ambrosius Aurelianus who rallied the Romano-British forces and led them to victory against their enemies, perhaps even at the battle of Mons Badonicus itself.
The end of independence
The conclusion of the struggle was victory for neither side. Sometime around the turn of the century a point of deadlock was reached. But whatever degree of unity had been established by the the Romano-British Revolt of 409 did not survive. The island of Britain was shattered into a myriad tiny kingdoms, to the east and the south the Anglo-Saxons ruled, to the west and north the native Brythonic Celts held sway.
The renewal of the struggle
A generation of peace followed this deadlock. But sometime around the middle of the century the struggle was renewed.
Some believe that it was The disaster of 535
and its consequent plagues and crop failures that fatally weakened the remnants of Roman civilisation within Britain and gave the insurgents the opportunity to extend their conquests.
But for whatever reason, the years between 550 and 650 sees the emergence of new Germanic kingdoms that relentlessly expand at the expense of their Brythonic neighbours. The veil of darkness begins to lift, revealing a new political landscape; in the north Northumbria, in the midlands Mercia and in the south the kingdom of the Gewissae (who soon transform themselves into the West Saxons of Wessex) had laid claim to the territory that stretched from Edinburgh to Exeter.
The end of Romano-Britain
As muddled and unclear as these sequence of events were, they remain the events that defined the future course of British history. For a thousand years or more there would be no Britain in a political sense. The Germanic Anglo-Saxons would eventually unite and reinvent themselves as the English whilst in the western peninsulas of Cambria and Dumnonia the remaining native kingdoms clung on to their own language and culture no longer Romano-British or even Brythonic, but now Welsh.
(1) The phrase Sub-Roman is derived from archaeology, or more specifically from the type of pottery manufactured during the period.
Generally speaking historians seem unhappy at having been lumbered with this title, but seem resigned to it, although they tend prefer snappier phrases such as, the lost centuries, the age of tyrants, the age of Arthur, the heroic age, the Brythonic age etc particularly when it comes down to the question of choosing that so important book title.
(2) As noted an authority as Christopher Snyder has stated that,
It is impossible to write a narrative history of Sub-Roman Britain
but this hasn't stopped others from trying, any more than it's stopped this particular author.
Firstly there are the historical sources themselves
or at least the available translations thereof. (Which are not that difficult to find online.)
Then there are the written sources consulted, mainly
- Peter Salway Roman Britain Oxford University Press (1978) - or principally chapters 15 and 16 that deal with the fifth century and which remains (to the best of my knowledge) the definitive textbook for the period of the Roman occupation
- Christopher Snyder An Age of Tyrants Penn State Press (1998) - no narrative, but the most up to date and authoritative work on the subject
- John Davies A History of Wales Allen Lane (1990)
- The ORB Encyclopedia section on Sub-Roman Britain at http://orb.rhodes.edu/encyclop/early/origins/rom_celt/subroman.html which has a good introductory essay by the above mentioned Christopher Snyder as well as links to other material.
- Vortigern Studies at http://www.vortigernstudies.org.uk/vortigernhomepage.htm which is fundamentally the most comprehensive website on the subject
- The Catholic Encyclopedia at http://www.newadvent.org/cathen/ which despite its ideological bias remains an invaluable source for early history