Post-Roman Celtic Kingdoms

Dumnonia (Dumnonii)

This large and well-founded kingdom took in all of Cornwall (Cornubia), Devon (Dyfneint), and much of Somerset. Its original capital would have been Isca (Exeter). Archaeology confirms that this site was abandoned in the fifth century, and, given the advances of the West Seaxe, the capital would continually have been relocated to the west. The main portion of Dumnonia in modern Devon (the Defnas, or 'deep valley dweller' Britons) fell to the West Seaxe between 652-685, while the Cornish remnant was still fully independent until 875.

The Dumnonii were basically a people with strong traditions reaching back unusually unmixed into the Bronze Age. In the eastern half of their territory, Devon west of the Exe, they appear to have used hill forts of the common type, but across the Tamar these virtually disappear and their place is taken by fortifications which are very similar to those in Brittany and Spain. Although under Roman control until the late fourth century, the Celtic tribe of the Dumnonii probably exercised a certain amount of self-government in their own lands (and may have been self-governed during Roman rule. See the Ancient Dumnonia page on the Dewnans Celtic Devon web site for an intriguing viewpoint on this).

They most probably re-established their kingdom as a power in its own right by the time of Magnus Maximus, as the latter prepared Britain's defences prior to establishing his own claim for control of the Roman Empire in AD 383, and Dumnonia was fully independent by 410, now also incorporating the former territory of the Durotriges.

(Additional information on Roman Dumnonia taken from The Oxford History of England: Roman Britain, Peter Salway.)

EXTERNAL LINK:
Dewnans Celtic Devon

c.55 - 75

The invading Romans occupy a legionary fort at Exeter.

c.290 - c. 305

Caradoc (Caratacus)

Trusted advisor of Eudaf Hen of Gwent.

[c.310

Mauric (Meurig)

First son. Heir, but predeceased Caradoc.]

c.305

Donaut (Dynod)

Second son. Left kingdom to his son-in-law, Conan.

c.340 - c.387

Conan Meriadoc / Conanus

King of Brittany. Left Dumnonia to his eldest son by Ursula.

c.387 - c.390

Gadeon (Cadfan)

Son. Half brother Erbin ruled Brittany.

c.390 - c.400

Guoremor (Gwrfawr / Vorimorus)

Son. Probably first independent King of Dumnonia.

c.400

By this time, Dumnonia has absorbed the former Celtic territory of the Durotriges in Dorset.

c.400 - c.410

Tutwal (Tudwal)

Son. Probably m Gratianna, youngest of Maximus' daughters.

c.410 - c. 435

Marcus Conomari (Conomor / Cynfawr)

Son.

c.435 - 443

Constantine Corneu

Son. Split the kingdom between his two sons.

443 - c.510

Cornubia is governed as a sub-kingdom by Erbin's younger brother, Merion. Upon his death, Cerniw is sub-divided to create an independent Lyonesse.

443 - c.480

Erbin (Urban) ab Custennyn

Abdicated in favour of Gerren before 480.

443 - al.500

Merchion ab Custennyn

King of Cornubia (Cerniw). (Line continues in Cerniw.)

c.480 - 508

Gerren (Gereint) Llyngesog ab Erbin

First son. ?Served with Arthur. Died at Portsmouth in 501?

[

Dywel ab Erbin

?Served with Arthur. ? d.c.520. Son may have been St Pirran.]

c.508 - c.530

Cado (Cadwy) ab Gerren

Duke of Cornubia & King of Dumnonia.

[

Iestyn (St Justin), Selyfan (Solomanus / St Selevan), St Breage

Second and third brothers to Cado and a sister. All entered the church.]

c.530 - c.560

Custennin ab Cado (St. Constantine)

High King until c.540. Entered a monastery. Killed 589.

c.560 - 598

Gerren rac Dehau ('for the South')

Son. Fought the Bernician Angles at Catreath.

577

Once the West Seaxe make the breakthrough of capturing Caer Baddan, Caer Ceri, and Caer Gloui, Glastenning and the heartland of eastern Dumnonia are under direct threat. However, it seems likely that the three cities had been receiving military support from Glastenning or Dumnonia, and that these kingdoms hold onto the West Wansdyke territory afterwards.

598 - 613

Bledric ap Custennin

Brother. Killed at Battle of Bangor-is-Coed by Aethelfrith.

597 - 611

The West Seaxe under Ceolwulf force the Dumnonians out of the West Wansdyke region of Caer Baddan (Somerset).

613 - ?    

Clement ap Bledric

Son.

614

Cynegils of the West Seaxe takes advantage of Bledric's death by invading Dumnonia. Badly defeated at the Battle of Beandun (Bindon, Devon), Bledric's son, Clemen, is forced to retreat back to Caer Uisc (Exeter), where archaeology suggests that a major Roman building was still being occupied into the seventh century.

c.630

Petroc Baladrddellt ap Clemen

652

Cenwalh makes a breakthrough against the Dumnonian defensive lines at the battle of Bradford-upon-Avon. Some areas of Dorset and Somerset fall.

al.658 - al.661

Culmin (Cwlfyn) ap Petroc

Defeated at the Battle of Peonna.

658

The West Seaxe are victorious at the battle of Peonna (Penselwood - the densely forested area on the eastern boundary of Somerset). The eastern half of Dumnonia is permanently captured by Wessex. The Brito-Welsh territory of Glastenning (in modern Somerset) is probably taken at the same time.

c.682

Dungarth ap Culmin

681 - 685

The West Seaxe conquer the remainder of Somerset as Centwine clears the western coastal area of Somerset as far as the Devon border. In a two pronged attacked the territory of the Defnas (Dumnonia / Devon) Britons is also taken by an army army pressing along the English Channel coast from Dorset to Exeter.

al.700 - 710

Gerren (Gerontius) ap Dungarth

Defeated by Ine of Wessex and killed.

c.710 - c.715

Ithel ap Dungarth

Probably ruled.

715

From this point onwards, the descent of the kings of Dumnonia becomes highly unreliable, as the kingdom is slowly crushed by Wessex.

by 800

The kingdom of Dumnonia, so compressed by the inroads made by Wessex, effectively ceases to exist. The remaining British territory is known as the Kingdom of Cerniu / Cernyw / Kernow (or Cornwall, meaning 'the Welsh of Corniu', to the Saxons).

825

The men of Cornish Dumnonia clash with the Wessex Saxons of Devon at the Battle of Galford. This is the first written record of the county of Devon in the Saxon form of the name.

c.865 - 875

Doniert (Dungarth / Duncan)

Possibly a descendent of Gerren. Drowned.

875

Doniert is traditionally said to be the 'last king', and is mentioned in Annales Cambriae as having drowned in 875.

c.927

Huwell

927

Cornwall falls to Athelstan and becomes a sub-kingdom much reduced in size with its rulers subordinated to the rank of Earl by the English. Much removed from the more important political happenings to the east, it manages to retain independence in all but name until the middle of the eleventh century.

Also during Athelstan's reign, a colony of Britons seems to have occupied its own quarter in Exeter until it is expelled by the king.

c.930

Conan

up to 1000

Ricatus

Land's End area only.

? - 1066

Caradoc

1066

The last native Earl of Cornwall is deposed by William the Conqueror of England.