The decline of Roman control over Britain was a
drawn-out affair which took perhaps a quarter of a century to
complete. That decline created a twilight period in which the
trappings of Roman civilisation and culture gradually faded out of
use and out of living memory.
The seeds were sown in the fourth century decline
that was seen throughout the Western Roman empire, as barbarian tribes
continued to make deeper incursions into Gaul, Hispania, and Italy,
and then began to settle. The rot had set in, and with it came rebellion,
lost territory, and subsequent losses in vitally-needed manpower and
resources. The period ended in a fog of obscure references and hazy
recollections which were often only written down generations later.
The decline in Britain was a slightly different affair
from that in Gaul. Britain was protected from the waves of barbarians
crossing the Rhine and the Danube, and only had to put up with the
marginally lesser problem of raiding Picts, Irish Scotti, and Saxons.
With hindsight, the decline of Roman influence in Britain
could be said to have started with the revolt of Magnus Maximus in AD 383
- not that it was seen that way by those living through that time.
The process ended in 409, when the Britons expelled
Roman authority from the country. The repercussions lasted much longer,
but the causes seem mostly to have come from overseas; from Gaul and
In 383 Maximus took advantage of the growing contempt for
failing Roman Emperor Gratian by revolting and invading Gaul with a large
army which was drawn from British garrisons. In preparation, he took various
steps to preserve the security of his powerbase. He shored up the defences
of Wales to protect the west coast from Irish raiders, making sure that it
was as strong as the east coast with its line of Saxon Shore defences. He
is generally credited with settling a band of Votadini warriors in North
Wales, and legitimised the settlements of Irish Scotti in south-western
Wales, setting up the Deisi to act as laeti there under a local
At the same time as this work was being carried out,
some of the Pennine and Welsh forts were abandoned and the Twentieth
Legion was withdrawn from Chester - both actions which can easily be
ascribed to Maximus.
In fact, his policy of shuffling forces around the
island and delivering others with clear cut defensive roles became
such a successful policy that the raids on Britain dried up in the
late fourth and early fifth centuries. The Irish Dalriata, instead
of trying to grab land in Roman Britain, went north beyond the Wall
to carve out a successful kingdom on the western edge of Pictland,
eventually forming Scotland out of it.
Maximus presumably selected Coel Hen as his
replacement to command in northern Britain, covering the vital
defences of Hadrian's Wall and 'governing' the semi-friendly
Britons between that and the Antonine Wall. Evidence on Coel Hen
is extremely murky, and more can be learnt about his role in
British history from the actions of his descendants than from him
directly. (Any mention of Coel Hen in an historical context is highly
controversial in some areas, usually those which refuse to believe
in the existence of Arthur.)
Maximus is also credited by Geoffrey of Monmouth
(far from reliable himself) with setting up the rebellious nephew
of Octavius, Conan Meriadoc, as ruler of Armorica, perhaps along the
same lines as the British leaders who apparently continued to claim
a high kingship in Roman Britain.
There certainly seems to have been the creation of
an independent authority in Armorica around this time, as well as an
increasing British influence which served to draw the region away from
Roman central authority in a series of rebellions so that, by 418, the
Britons of Armorica were acknowledged as being almost completely
independent of Rome.
The reorganisations by Magnus Maximus and his
withdrawal of some army units from Britain almost signals the end
of direct Roman rule over the island. There was a central
administration, true, and even a mint at London during Maximus'
reign, but the island rarely came under direct control from Italy
after this point.
As if to underline this, from this date forwards,
all names that are claimed as being high kings of Britain originate
from within the country whereas for the previous three hundred years
they had included a large number of Roman emperors. The British
perspective on who ruled them had clearly undergone a change.
Part of a hypocaust displayed in the Roman Gardens in
View the Roman invasion and conquest in a series
of detailed maps.
Pursuing the purple
Magnus Maximus left Britain in AD 383 in pursuit
of his claim to the purple (command of the empire itself). He made
extremely good headway in Gaul, securing Armorica (which now commenced
its role as a sister-state of Britain), and then heading towards the
south. After defeating Emperor Gratian and forcing Valentinian III out
of Rome, Maximus set up his court at Augusta Treverorum (Trier) and by
all accounts became a popular emperor.
He took with him all those troops that had been freed
up by his reorganisations, and apparently left the island in a fairly
good defensive position despite the loss of good, Roman-trained troops
who apparently never returned to Britain. Did this drain on manpower
make a difference? If it didn't make a real difference (due to the
reorganisations) then it may well have made a perceived difference
amongst the barbarians to the north. They could scent an opportunity
in the making.
It seems that between 384 to 390 warfare flared up
with the Picts again and, according to Gildas (referring to it as
the first of his 'Pictish wars'), it lasted 'for many years'.
However, Maximus himself hardly betrayed the signs
of someone who had a major battlefront in his read, especially when
he launched an attack on Italy in 387 (which, ultimately, was
ill-fated, but due only to the better generalship of his opponent),
so the situation was probably contained satisfactorily by his deputy
in Britain, at least up to this date.
Maximus lost his own war and was executed in 388.
Upon his death, the situation in Britain may have worsened. Perhaps
the barbarians had learnt of events on the Continent and saw that the
time was right. They are believed to have attacked south of Hadrian's
Wall although no details are known, and the Britons, overwhelmed, sent
a plea for assistance to the emperor.
The Roman basilica in Trier
(click or tap on image to read more on a separate
Emperor Theodosius, who had defeated Maximus, waited.
The Britons were forced to send assurances of their renewed loyalty
to him before he dispatched a legion, probably by 390, to help stop
the Pictish attacks. This 'legio' may not have been a Roman legion
in the traditional sense, but more of a specialist taskforce, something
that was becoming more frequent in the Western Empire at this time.
The taskforce must have done its work to end the immediate
threat. Gildas states that rebuilding work took place on the two Roman
walls afterwards, with the Britons being instructed on this process,
suggesting that the taskforce was not to stay and the Britons must
look increasingly to their own defence.
In fact, it seems likely that the legion did become
semi-permanent (and there is a proven tendency for armies or imperial
comitatenses (in effect, royal guards units), each under a
comes, to become localised, acquiring local titles.
Britannia was again isolated from Rome by the revolt
of Arbogast and Eugenius in 392-394, but this revolt took place entirely
on the Continent, in Italy, and in the Balkans, so the island probably
wasn't directly affected. How the Britons saw the situation is anyone's
guess, but it may have had implications for their later actions in
relation to imperial control over the island.
Fundamental changes to imperial practices
The accession of Honorius and Arcadius in 395 was marked
by a basic change in the role of the emperor. It affected the east and
west differently, and what happened is of major importance in
comprehending what occurred subsequently in the two halves of the empire.
Roman emperors after Theodosius were heads of state but no longer held
effective power. This now fell into the hands of their chief ministers.
The change was complete in the west, but less so in the
east where occasional emperors still took direct command. Perhaps the crucial
difference was that in the east the ministers were usually civilians, but in
the west they were almost without exception professional soldiers who tended
to dominate their emperors.
Emperor Theodosius I the Great brought a period of renewed stability
to the empire
Due partially to this, and to a series of problems,
Honorius' reign was characterised by periods of chaos and the erosion
of the Western Roman empire and its territories. Successive chief
ministers played politics to ensure their own survival, that of the
empire, and sometimes that of the emperor himself, but despite the
best intentions of the best of them, the empire rarely benefited in
the long term. When Honorius died he left an empire on the verge of
However, while he was still alive there were clearly
battles to be fought. In 398, according to the poet Claudian, it
appears that Roman forces were able to assert control over the sea
approaches to the north-western provinces, and this also included
defeating both Saxons and Irish Scotti off the coast of Britain.
It is not clear whether the Picts, also mentioned as
being beaten, are included as seaborne enemies or whether their mention
is intended to refer to a purely land-based campaign, which overall has
been linked to the second of Gildas' 'Pictish wars'.
However, it seems possible that there was no such
victory in 398, and the chief minister, or prefect, in the west,
Stilicho, who had already been abandoning forts at the beginning of
his regency, merely attended to the island's defences before withdrawing
more troops, probably the previously settled taskforce, thereby further
running down the garrison of Britain.
Did Stilicho ever win a victory against
Saxons and Scotti off Britain's coast in AD 398, or was it
Again scenting weakness while Rome was occupied by
the usurper Gildo in Africa, the barbarians took the opportunity to
attack. This time they were thrown off-balance by the unexpected collapse
of Gildo's forces in Africa and did not press home their attack.
Finally, although the planned withdrawal was resumed,
the warning was heeded and measures were taken to strengthen the defences