Eagles Have Flown

The well-known date of Britain’s final official break from Rome is AD 410, but by that stage Roman Britannia had mostly been fighting its own battles for nearly thirty years with only occasional support from Rome. It was forced to look after its own interests in the face of increasing barbarian raids; from the Picts to the north, the Scotti and Irish to the west, and from various Teutonic tribes to the south and east.

There had been frequent barbarian raids throughout the fourth century in Britain. The Barbarian Conspiracy in 367 was a three-fold attack by Teutons from across the North Sea, and Picts and Scotti from the north and west.

Magnus Maximus

The next crisis faced by Britain came in 383, when the military commander, Magnus Maximus, realised that Roman power in the region was becoming increasingly toothless, and made his own claim to imperial power, supported by the army. His death in 388 deprived the island of the greatest part of its military strength, although the reorganisations usually attributed to him shored up the north and western coasts of Britain. However, there appears to have been almost continual warfare against the Picts during this period.

In about 398, Britain apparently had to be rescued from her barbarian foes, this time by the most powerful general of the Western Roman Empire, Stilicho. Stilicho’s intervention was the last occasion on which a major expedition was mounted against the enemies of Britain.

Soon after the situation had been retrieved, Roman forces on the island were further reduced to serve Italy against the invading Goths. By 406, Britain’s military strength had been largely drained away, and the following decade completed the process.

In 406 a vast army of barbarians crossed the frozen Rhine and began advancing westwards towards the Channel coast. It began to appear as though Britain might be invaded.

Constantine III

Earlier in the same year, the army in Britain had already elevated an unknown soldier, Marcus, to supreme power. He did not last long, being supplanted at the time of the barbarian advance through Gaul by Gratian, an urban magistrate (magistratum). Gratian survived only four months, and the army’s next choice fell on a soldier, Constantine, who challenged Roman authority in Gaul, creating a prefecture at Arles from which to rule as Emperor Constantine III.

Constantine had, in 407 removed at least something of Britain’s remaining trained forces only to be killed in 411 at Arles. The troops never returned but instead may have largely settled in Armorica, paving the way for a later British migration there.

In 408/409, Britain was subjected to a large-scale barbarian invasion, probably by Saxons, with Anglian support.

The British civitates – the urban centres – managed to defend themselves and by 409 had quelled the attack, although details of how they did this are not available. It is possible that many of the surviving defeated Saxons and Angles were employed as foederati – mercenary troops – to garrison the Saxon Shore (the east coast) and protect it from further attacks. Although this was established Roman practise, and undoubtedly in use before this time, this action would help to explain the large number of Teutonic sites along Britain’s east coast that are evident from before the Adventus Saxonum in 450.

Abandonment by Rome

In 410, the feeble emperor Honorius informed the internal government of Britain that it would have to look after its own defence, implying that this would be a permanent arrangement. During what was either a revolt of peasants and slaves in Britain in 409 to mirror either the popular uprising of the oppressed classes in Armorica (Brittany), or at the tail end of the barbarian invasion, the Romano-British governor had appealed for imperial help.

In the face of this abandonment by Rome, the defence of Britain was left to the western and northern kingdoms and whatever remained of the central government, essentially operating under a traditional Celtic High King, who may well have used the title Emperor of Britain while it still meant anything.

Theoretically, Vortigern could have been the first of these, with Ambrosius Aurelianus, and Arthur following them (Uther Pendragon is harder to pin down, but would have ruled between Ambrosius and Arthur, unless, of course, he was in reality the same person as Ambrosius, an argument not within the scope of this feature).

Border client kingdoms

Welsh tradition has long held that Magnus Maximus arranged the island’s defences before making his expedition abroad to claim the Imperial title. Other sources attribute some of the changes to Vortigern, so a combination of the two is highly likely. Magnus Maximus, though, began the work, and seems likely to have made the biggest changes. What he did was to arrange large defensive areas that could be governed by client tribes or native Roman officers.

All of these were set up in the militarised zones, in the west and north, areas that had never been fully Romanised and had been under military control through several chains of forts. The borders shown in the map below are mostly conjectural, but are based on later kingdoms that emerged in these areas, through the inevitable fragmentation that occurred when Celtic tradition demanded an equal distribution of land between surviving sons.

The south and east, areas far more greatly Romanised, came under the island’s central administration, for as long as it lasted. This explains the proliferation of early independent Celtic kingdoms in the west and north, while the heart of the Celtic Lloegr (ie. England) was much slower to fragment, and perhaps because of that, was a much easier area from which Angles and Saxons could grab territory.

However, kingdoms did emerge in the south and east, mostly towards the end of the fifth century, and some of these left evidence of their survival, if not their names. (details of these can be accessed from the next map in the series, The Island of Britain).

from Kessler, P. L. (2007, September 8). Post-Roman Britain: Early Independent Britain AD 400-425. Retrieved from http://www.historyfiles.co.uk/FeaturesBritain/BritishMapAD400.htm

Eagles Have Flown