Post-Roman Britain

Sub-Roman Britain is the period of late antiquity in Great Britain between the end of Roman rule and the Anglo-Saxon settlement. The term was originally used to describe archaeological remains found in 5th- and 6th-century AD sites that hinted at the decay of locally made wares from a previous higher standard under the Roman Empire. It is now used to describe the period that commenced with the evacuation of Roman troops to Gaul by Constantine III in 407 and to have concluded with the Battle of Deorham in 577.

Meaning of terms

The period of sub-Roman Britain traditionally covers the history of the area which subsequently became England from the end of Roman imperial rule, traditionally dated to be in 410, to the arrival of Saint Augustine in 597. The date taken for the end of this period is arbitrary in that the sub-Roman culture continued in northern England until the merger of Rheged (the kingdom of the Brigantes) with Northumbria by dynastic marriage in 633, and longer in the West of Britain, and Cornwall, Cumbria and Wales especially.

This period has attracted a great deal of academic and popular debate, in part because of the scarcity of the written source material. The term "post-Roman Britain" is also used for the period, mainly in non-archaeological contexts; "sub-Roman" and "post-Roman" are both terms that apply to the old Roman province of Britannia, i.e. Britain south of the Forth– Clyde line. The history of the area between Hadrian's Wall and the Forth–Clyde line is similar to that of Wales (see Rheged, Bernicia, Gododdin and Strathclyde). North of the line lay a thinly populated area including the kingdoms of the Maeatae (in Angus), Dalriada (in Argyll), and the kingdom whose ''kaer'' (castle) near Inverness was visited by Saint Columba. The Romans referred to these peoples collectively as '' Picti'', meaning 'Painted Ones'.

The term "late antiquity", implying wider horizons, is finding more use in the academic community, especially when transformations of classical culture common throughout the post-Roman West are examined; it is less successfully applied to Britain at the time. The period may also be considered as part of the early Middle Ages, if continuity with the following periods is stressed. Popular (and some academic) works use a range of more dramatic names for the period: the Dark Ages, the Brythonic Age, the Age of Tyrants, or the Age of Arthur.

Written accounts

There is very little extant written material available from this period, though there is a considerable amount from later periods that may be relevant. A lot of what is available deals with the first few decades of the 5th century only. The sources can usefully be classified into British and continental, and into contemporary and non-contemporary.

Two primary contemporary British sources exist: the ''Confessio'' of Saint Patrick and Gildas' ''De Excidio et Conquestu Britanniae'' (''On the Ruin and Conquest of Britain''). Patrick's ''Confessio'' and his ''Letter to Coroticus'' reveal aspects of life in Britain, from where he was abducted to Ireland. It is particularly useful in highlighting the state of Christianity at the time. Gildas is the nearest to a source of Sub-Roman history but there are many problems in using it. The document represents British history as he and his audience understood it. Though a few other documents of the period do exist, such as Gildas' letters on monasticism, they are not directly relevant to British history. Gildas' ''De Excidio'' is a jeremiad: it is written as a polemic to warn contemporary rulers against sin, demonstrating through historical and biblical examples that bad rulers are always punished by God – in the case of Britain, through the destructive wrath of the Saxon invaders. The historical section of ''De Excidio'' is short, and the material in it is clearly selected with Gildas' purpose in mind. There are no absolute dates given, and some of the details, such as those regarding the Hadrian's and Antonine Walls are clearly wrong. Nevertheless, Gildas does provide us with an insight into some of the kingdoms that existed when he was writing, and how an educated monk perceived the situation that had developed between the Anglo-Saxons and the Britons.

There are more continental contemporary sources that mention Britain, though these are highly problematic. The most famous is the so-called ''Rescript of Honorius'', in which the Western Emperor Honorius tells the British ''civitates'' to look to their own defence. The first reference to this rescript is written by the 6th-century Byzantine scholar Zosimus and is found in the middle of a discussion of southern Italy; no further mention of Britain is made, which has led some, though not all, modern academics to suggest that the rescript does not apply to Britain, but to Bruttium in Italy. The Gallic chronicles, ''Chronica Gallica'' of 452 and ''Chronica Gallica'' of 511, say prematurely that "Britain, abandoned by the Romans, passed into the power of the Saxons" and provide information about St Germanus and his visit or visits to Britain, though again this text has received considerable academic deconstruction. The work of Procopius, another 6th-century Byzantine writer, makes some references to Britain, though the accuracy of these is uncertain.

There are numerous later written sources that claim to provide accurate accounts of the period. The first to attempt this was the monk Bede, writing in the early 8th century. He based his account of the Sub-Roman period in his ''Historia ecclesiastica gentis Anglorum'' (written around 731) heavily on Gildas, though he tried to provide dates for the events Gildas describes. It was written from an anti-Briton point of view. Later sources, such as the ''Historia Brittonum'' often attributed to Nennius, the ''Anglo-Saxon Chronicle'' (again written from a non-Briton point of view, based on West Saxon sources) and the ''Annales Cambriae'', are all heavily shrouded in myth and can only be used with caution as evidence for this period. There are also documents giving Welsh poetry (of Taliesin and Aneirin) and land deeds (Llandaff charters) that appear to date back to the 6th century.

After the Norman Conquest there were many books written that purport to give the history of the Sub-Roman period. These have been influenced by the fictionalised account in Geoffrey of Monmouth's ''Historia Regum Britanniae'' (''History of the Kings of Britain''). Therefore, they can only be regarded as showing how the legends grew. Not until modern times have serious studies of the period been undertaken.

Later ''Lives'' of Celtic saints, although often unreliable, do provide some insights into life in Sub-Roman Britain. For example, there is a description of a dilapidated, but still occupied, Roman villa near Chepstow (probably at Portskewett) included in an account of a visit by St Tatheus; and the Roman ruins of Carlisle, as they were in 685, are described in a ''Life'' of St Cuthbert.

Archaeological evidence

Archaeology provides further evidence for this period, though of a different nature from that provided by documents. Archaeology suggested to Richard Reece that the depopulation of Roman towns and the development of villa and estate organization was already occurring in the 4th century.

The 5th and 6th centuries in Britain are marked by a sharp discontinuity in town life, perhaps always a somewhat artificial Roman imposition on the landscape, dependent on imperial military requirements and requirements of administration and tax collection; the exceptions are a handful of sites: Londinium, Eboracum, Canterbury, Wroxeter and possibly Cambridge, but the discontinuity in the episcopate, "the institution most responsible for the survival of towns in Gaul", as H. R. Loyn observes, speaks against town survival in Britain.

The Roman villa system, represented by some five hundred archaeological sites, did not survive either; unlike Gaul, in Britain not a single villa name survived into the Germanic period (however, at ''Chedworth villa'' a mosaic within Room 28, discovered in 2020, was designed and created in the middle of the 5th century). It may be possible that the villa system did not survive the disastrous Pictish incursions in 367 and following years.

In the sub-Roman period, building in stone came to an end; buildings were constructed of less durable materials than during the Roman period. However, brooches, pottery, and weapons from this period have survived. The study of burials and cremations, and the grave goods associated with these, has done much to expand the understanding of cultural identities in the period. Archaeology has shown some evidence of continuity with Roman education, trade with the Mediterranean, and with Celtic art.

Excavations of settlements have revealed possible changes in social structures, and to what extent life in Britain continued unaltered in certain pockets into the early medieval period. Hilltops, the so-called "hillforts", '' castra'', and monasteries have been excavated. Work on towns has been particularly important. Work on the hill-forts has shown evidence of refurbishment, and also of overseas trade, in this period. One of the earliest major excavations was at Tintagel (Radford 1939). This uncovered rectangular structures and much Mediterranean pottery. The buildings were initially interpreted as a monastery, but