The collapse of Roman rule in Britain, followed by the emergence of kingdoms established by Germanic tribes, marks one of the most turbulent periods in Britain’s history. But what factors drove this dramatic transformation? Nick Higham chronicles the rise of the Anglo-Saxons
Throughout history, many Scots have harboured a lingering mistrust of the English. Plenty in Wales felt similarly. Edward I, the ‘Hammer of the Scots’ who also conquered swathes of land west of his kingdom, must take much of the blame. But the fundamental roots of these tensions stretch back to a time centuries before that bellicose English king, to the slow, messy, turbulent collapse of Roman Britain and the arrival of the Anglo-Saxons.
A whistle-stop précis of the textbook history goes something like this: Iron Age Britain was inhabited by tribes of Celts. Then came the Romans: nearly 100 years after Julius Caesar’s exploratory forays, in AD 43 the Emperor Claudius launched an invasion. Within half a century, the southernmost two-thirds of the island was conquered, creating the Roman province Britannia. As part of the Roman empire, it was subject to externally appointed governors and protected by its army.
But in the fifth century – the pivotal year often cited is 410 – events in continental Europe drove the Roman authorities to abandon Britain. Within a few decades, Roman-style artefacts had been replaced in the archaeological record of eastern Britain by metalwork, pottery, burial styles and buildings indicative of ‘Anglo-Saxons’ – an umbrella name coined later to encompass Germanic tribes known as Angles, Saxons, Jutes and Frisians from north-west Europe. These settlers – or invaders – were those described by Bede in 731 as gens Anglorum: English people.
It’s a neat story, and one with which many readers will be familiar. However, it’s also a story that raises a number of questions. What drove the collapse of Roman rule in Britain? How did Britain differ from its neighbours on the continent in this period? What attracted Anglo-Saxons to Britain from the fifth century? And how, by the beginning of the seventh century, were they well on their way to becoming the dominant force across much of the British Isles?
To answer these questions, we must first examine the relationship between the people of Britain and the Roman administration through those centuries of imperial rule. The bonds that tied Britain to Rome – or, more to the point, the lack of them – would have an enormous impact on what happened after that relationship began to fracture.
Regional divide
During the Roman period, there were key differences between Britain’s western uplands and its less-hilly eastern areas. In the west, the dominant language remained Celtic Brittonic, evolving into Welsh. Towns, villas, manufacturing facilities, extensive field systems, mosaics and churches were lowland phenomena, leaving the westerly uplands as military spaces – particularly in the north – or areas given over to pastoralism.
Yet a key point here is that, even in lowland Britain, the Brittonic language survived. Britons were barely engaged in imperial frameworks: none was made emperor before 400, nor did any Briton enter the Roman senate or attain high office. To Rome, Britain was always liminal, its inhabitants mere “savage ploughmen”, as the Gallo-Roman poet Rutilius Namatianus put it.
During the Roman period, there were key differences between Britain’s western uplands and its less-hilly eastern areas
True, Britain’s fertile lowlands contributed taxes in cash and in kind, and sufficient profit for landowners to commission sometimes lavish Roman-style villas. But in 353, these landowners’ peace was shattered by the defeat of the usurper western Roman emperor Magnentius at the hands of his eastern rival, Constantius II. Magnentius’s defeat was followed by savage reprisals in Britain, where he had enjoyed support. The contemporary soldier-historian Ammianus Marcellinus wrote that Constantius’s notoriously cruel representative Paulus Catena (‘Paul the Chain’) “descended like a sudden torrent upon persons and estates”, whether guilty or not.
This was a critical moment in the decline of Rome’s influence in Britain. Catena’s violent intervention seems to have triggered a transfer of confiscated property to overseas magnates – which may explain why so many villas became derelict. The resulting economic haemorrhaging from the province lowered demand and stifled manufacturing, importing and service industries. Britain suffered, economically and socially.
The chaos didn’t end there. Across the final quarter of the fourth century, western Roman armies endured further defeats in civil wars, leaving them undermanned, ill-funded and politically impotent. Britain’s northern garrisons may have remained largely in post following this tumult but, crucially, Britain’s lowlands to the east were undefended, opening the door to seaborne attacks.
Britain was part of the Roman empire for perhaps 14 to 18 generations. During that time, imperial protection had invariably been reimposed following crises. This time, though, was different. Honorius (emperor from 393 to 423) is recorded as responding to a plea for aid by advising British towns in 410 that they would need to defend themselves. This would have been understood by all sides to be an interim strategy pending the return of normal Roman governance to Britain. However, barbarian intruders and internal struggles on the continent continued to prevent the Roman recovery of Britain.
Edge of empire
Post-410, then, Britain was neither properly inside nor truly outside the empire, and the likelihood of intervention by western Roman forces oscillated according to circumstances across the Channel. Even so, archaeological finds imply that members of Britain’s elite retained much of their power, adhering to Roman dress codes until the third quarter of the fifth century. They continued to increase their commitment to Christianity, by then the imperial religion, and enjoyed ongoing access to Roman-style education, evidenced in Latin works by Britons including Gildas, a learned sixth-century church deacon.
As late as 429, a bishop from Gaul took command of British soldiers confronting Saxons and Picts, indicating continued efforts to deter attacks despite the lack of military expertise locally. According to one fifth-century writer, Britain remained “a very wealthy island” that the military-minded bishop “rendered secure in every sense” – against both heretics and ‘barbarians’, as Romans termed pagan tribes who didn’t speak Latin. Despite those efforts, though, Britain’s lowlands remained vulnerable to barbarian incursions. A Gallic chronicler noted Saxon raiding in 410, and Gildas knew of Pictish and Scottish assaults.
Meanwhile, it seems there was a shift away from agriculture towards livestock, presumably resulting in a falling tax-take, but another source of income was found. Land previously exploited on behalf of the state or overseas magnates (absentee Roman landowners) likely provided resources that could be used to pay mercenaries to replace the depleted garrisons. This measure, intended to be temporary, meant recruiting barbarians – often men from the Germanic tribes that would become known as the Anglo-Saxons – to help defend against sea-raiders. And it had far-reaching consequences.
Recruiting barbarians to help defend against sea-raiders was a measure that would have far-reaching consequences
The earliest Anglo-Saxon cemeteries in Britain date from c420, so people from northern Europe had clearly begun settling by then. From such sites, including Spong Hill in Norfolk, we can infer that incomers arrived mostly across the decades from around 420 to 460. Anglo-Saxon – and, occasionally, Irish – artefacts found farther inland can be taken as evidence that barbarians were also hired to provide internal security or as bodyguards.
The patterning of Anglo-Saxon cemeteries in, for example, Lincolnshire and Sussex is consistent with settlement initially overseen by British regional rulers. In the long term, though, employing barbarians against attacks potentially launched by their own kin was risky. Mercenaries had more to gain by increasing their own numbers and dispensing with local elites altogether.
Aggressive incomers
Our Gallic chronicler reported that, c441, “the British provinces… were reduced to the rule of the Saxons”. This seems simplistic, and was written at a considerable distance, but it does suggest that incomers had by then seized regions perhaps including Norfolk and the east Midlands.
Gildas noted that Britons sought aid from the western Roman general Flavius Aetius in defending themselves against Picts and Scots between 446 and 454, but no help arrived; Flavius’s assassination in the latter year effectively ended any prospect of Rome’s return to Britain. It was at this point in his narrative that Gildas began remarking on British kings, perhaps implying that some kind of government was emerging in a Britain independent of Rome.
One leader named by Gildas, writing the following century, was Ambrosius Aurelianus. He is described by Gildas as being Roman, with parents who had “worn the purple” – suggesting a continental family who had attained wealth and power in Britain. This war leader reportedly led a British force to victory over Saxon raiders.
The pivotal figure in these struggles, though, was apparently a man Gildas described as a “proud tyrant”. This ruler, named Vortigern by Bede, hired further Saxons from overseas and supplied them via Roman-style taxation in kind. The ninth-century Historia Brittonum (History of the Britons) provides Vortigern’s genealogy, indicating his descent from a Christian Roman family connected with Gloucester.
That location suggests that the political focus had shifted from the south-east to the still-wealthy lowlands at the heart of the western province Britannia Prima, ruled from Cirencester. Recent excavations at nearby Chedworth villa have revealed a mosaic floor laid no earlier than the second quarter of the fifth century, implying that investment in Roman material culture and social norms continued significantly later here than it did farther east.
Act of folly
To Gildas’s mind, the hiring of ‘barbarians’ to defend the eastern coast – though common Roman practice – was an act of folly, leading to their rebellion and a great raid “from sea to sea”. While victories were won by both sides, and despite British success at the siege of Mons Badonicus (Badon Hill, which some think may have been Little Solsbury Hill near Bath, or Badbury Rings in Dorset) around the turn of the sixth century, the Saxons ultimately triumphed. An unnamed treaty to end the war, referred to by Gildas, seems to have recognised Saxon control of most of lowland Britain.
Our knowledge of Anglo-Saxon population numbers, movements and interactions in this period suffers from a paucity of relevant material evidence. But, certainly in the more open, lower-lying regions of the south and east, a substantial labour force must have worked the land, implying that numerous Britons survived external takeover and remained in those areas – albeit not always toiling for their own benefit.
Gildas noted that many of his grandparents’ generation were “made slaves forever”. Tellingly, the Old English wealas – from which ‘Welsh’ derives – meant both ‘foreigners’ and ‘slaves’. Unfree agriculturalists appear in early English law documents. And when Bishop Wilfrid was granted the Selsey estate by the formerly pagan South-Saxon king in the 680s, it came with 250 slaves. Most such enslaved people were almost certainly of British ancestry.
Again, the patchy nature of Anglo-Saxon material culture in the archaeological record from this period makes it difficult to plot accurately the English presence versus enduring British populations. One hint comes from Bede who recorded a war against British adversaries won by the Anglo-Saxon king Æthelfrith of Northumbria in c600. As a result, some defeated regions were forced to pay tribute, while others were settled.
In his polemical De Excidio et Conquestu Britanniae (On the Ruin and Conquest of Britain), Gildas compared events in Britain to the occupation of Judea by Assyrian forces detailed in the Old Testament. He painted the Saxons as ungodly incomers to be expelled, not assimilated.
That view contrasts with the near-contemporary willingness of Gallo-Roman bishops to baptise Franks and Burgundians. So Germanic tribes were being embraced by Christians on the continent while racial, ethnic and ideological distinctions were reinforced in Britain. Clearly, England was established through warfare. But the incomers were encouraged to invest in their inherent German-ness by the racial and ideological hostility they encountered.
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The result was that Britain came to host the largest pool of pagans anywhere in Roman (or formerly Roman) western Europe. Frankish kings sought to spread Christianity in south-east Britain in the later sixth century, and in the 590s Pope Gregory I sent Italian monks led by Augustine to Canterbury, assuming that British clergy would assist his missionaries. They didn’t, instead clinging to their expectation that God would expel the ‘barbarians’.
The incomers were encouraged to invest in their German-ness by the racial and ideological hostility they encountered
In consequence, Christianity in Britain fractured. Rome’s mission dismissed the Britons as heretics, and threw its considerable ideological weight behind the new English converts. The combination of Rome’s religious authority and Anglo-Saxon secular power triggered the wholesale acculturation of Britons wherever they were vulnerable, undermining the Welsh language and British identity throughout England. People of Welsh and British ethnicity were increasingly restricted to regions subject to British lords, lands distant from both English kingship and the Anglo-Roman clergy.
Difficult relationship
That rift sealed the fate of the British – and the dominance of the English in the lowland south and east of the island. But the foundations of England and its cultural robustness have far deeper roots. The triumph of the Anglo-Saxons can ultimately be traced to Britain’s problematic relationship with the Roman empire. The Britons’ retention of a Celtic language, their absence from imperial structure, the fact that much of their island’s best agricultural lands were owned by magnates overseas, the fact that they identified primarily with Britain – all contributed to a peripheral status in the Roman world. So when the Saxon mercenaries they hired to help defend Britain against other ‘barbarians’ rebelled, Britons were isolated and vulnerable, receiving no assistance from their former imperial rulers.
The northern uplands of what is now England and south-eastern Scotland fell to Anglo-Saxons across the later sixth and seventh centuries, leaving British communities under their own kings only in the Clyde valley, alongside those in Wales and Cornwall. Here Celtic survived, along with the belief that, when God willed, the English would be forced out. The 10th-century Welsh poem Armes Prydein (The Prophecy of Britain) predicted a time when Saxons would be expelled from the stolen lands and the British people would recover all Britain. They’re still waiting.
This article was first published in the July 2026 issue of HistoryExtra Magazine
Authors
Nick Higham is professor emeritus at the University of Manchester. He is the author of King Arthur: The Making of the Legend (2018).