Some sub-Roman territories or kingdoms are better attested than others.
Those in the south-west may not have survived longer than some of their
eastern counterparts, but they seem to be mentioned more often.
Caer Gloui (with Caer Baddan and Caer Ceri)
To the south of Pengwern lay the Romano-British cities of Caer Gloui (Roman
Glevum, modern
Gloucester in Gloucestershire), Caer Ceri (Roman Corinum, modern Cirencester in Gloucestershire) and Caer Baddan
(Roman Aquae Sulis, modern Bath in Somerset). The colonia of Gloucester was founded by Rome
around the start of the second century.
It is known that small kingdoms existed here in the sixth century,
although their names are not known. Ambrosius Aurelianus, strongly linked to the south
west, also seems to be linked to Caer Gloui (and the 'three cities'
territory), so perhaps this was his main base. It seems highly possible that
the later splintered kingdoms were a single political entity in his time, and were
subsequently handed out between descendants (Nennius calls the
region Guenet).
In fact, the centre of Ambrosius' power in the mid- to late-fifth
century can only lay in one of two places, and of those,
Caer
Celemion seems less likely. The three
cities territory, lying in central Wiltshire, west of the hinterland of the
Saxon Shore, and extending from upper Somerset to Gloucester was an area not
yet remotely threatened by Cerdic and his people in Hampshire.
And here, strategically situated in the Avon valley, almost due south of the central
section of East Wansdyke at Wodnesgeat, some fourteen miles away across the
Vale of Pewsey, is Amesbury, which in a charter of about 880 was spelt
Ambresbyrig, 'the stronghold of Ambrosius'. Nowhere could be better suited
to be the focus of Ambrosius' operations.
According to archaeological evidence, Caer Ceri continued as a centre for
civic life in the 440s; the defences were repaired, flood prevention work was carried out
on one of the gates, and the piazza of the forum was kept clean. But in 443 the whole
Roman world was swept by a plague, the severity of which has been compared to the Black
Death, and this hit Britain in around 446. At the same time as the Anglo-Saxon mercenaries in
the east revolted, unburied bodies were to be found in Caer Ceri's streets, and the town
seems to have contracted to some small wooden huts inside the amphitheatre.
The Romano-British must have recovered from the mid-century plague. The next major event for the territory was Ælle's attack on
Mons Badonicus in circa 496. The
route the Saxon forces took was probably westwards along the upper
Thames
Valley and through the Goring Gap.
It seems creditable to assume that the north-facing Wansdyke, constructed in the fifth or
sixth centuries (and which roughly follows in part the proposed upper section of Caer Baddan's
eastern border where it leads to the northwestern border of Caer Celemion), was put up by
sub-Roman forces in Wiltshire in the face of just such a threat.
It could either have been constructed to ward off this very
attack from the direction of the Thames Valley (and perhaps channel the attackers towards Badon), or in response to
it, to ensure that no future attacks of this nature could take place. In
that it was very effective, until the
West Seaxe conquered the
heart of Wiltshire in 552.
No doubt greatly heartened
by their victory at the end of the century, the sub-Roman presence continued to hold out.
For much of the early sixth century (at least until 534, and maybe as late
as 560) they remained in general unmolested.
In 577, the West Saxons set great store by the fact that the final kings of the three
cities were killed fighting them at the Battle of Dyrham (Gloucestershire).
The territory was taken over by the Hwicce,
who apparently merged with the existing Briton population. The West Wansdyke region of Caer Baddan
seems to have remained in Dumnonian hands (or those of Glastenning) until
597-611, when it fell to the West Seaxe.
Eastern Dumnonia
On Britain's south coast, the modern Dorset area remained in British hands until
at least the mid-seventh century.
Given the dominance of Dumnonia over the whole of the south
west, it is unlikely there was an independent kingdom here, but either Caer Durnac (Roman
Durnovaria, Dorchester in Dorset - from the former Durotriges tribe of this
territory) or Wareham (the site of several early British memorial stones) may
have hosted a regional power base, or sub-kingdom.
Its name is unknown but extrapolating from Dorset's modern name, and the fact
that Saxon settlers in the area called themselves the Dormsaete, the name
Dorotric, or Dortrig, is not impossible. Defnas (Devon) has also been used for the
neighbouring area to the west, probably to
indicate the Britons there.
Nothing outside of the traditional story of Vortigern's betrayal by his Jutish foederati
is known of Post-Roman Kent. It cannot have remained a free territory for more than a generation before being captured by Hengist and Horsa
between 450-455.
They were given land there in 450, and began their revolt later the same
year. But Ceint was definitely a British kingdom in 450, and may have been established by
the time Vortigern became High King in around 425. Its capital would have been Durovernum
(Canterbury).
The story of its capture ascribed a King Gwyrangon as its ruler. Doubtless
he became one of Vortigern's staunchest detractors when he found the High King had given
his kingdom away to barbarians, but he must have put up a fight. The Anglo-Saxon
Chronicle depicts two major battles, Agæles threp (Aylesford in Kent) in
455 and Crecganford (Crayford) in 456, before the British are said to have given
up on Ceint and retreated to London.