Mighty Dumnonia: Dark Age Politics, Part 12

Today we’re looking into one of the most important British kingdoms that emerged from the end of Roman Britain. Most people know it as Dumnonia, a Latinized version of the early British tribal name. It becomes Dyfneint in later Welsh, eventually developing into Devon. In my historical fiction series, The Arthurian Age, I use a name more likely to have been used in Arthur’s time: Dumnein.

Dumnonia encompassed modern Cornwall, Devon, and part of Somerset. For two millennia before Rome conquered the region, it was a prosperous center of trade and culture, primarily due to tin. This important metal, combined with copper, made the alloy that gave the Bronze Age its name. It was traded as far as the eastern Mediterranean. Tin continued to be an important export until near the end of the 20th century.

Rough Boundary of Dumnonia at its height in the 5th Century.

Rome established one legionary fort in Dumnonia at Exeter in 55 AD, and the region was fully under Roman control within a generation. Yet, Dumnonia was one of the least Romanized areas of Britain, with few villas or Roman roads. It appears the Dumnonians were allowed a remarkable degree of self-governance under Roman rule. This may be why Dumnonia became such an important and powerful kingdom. Welsh legend says Dumnonia had kings more than a century before the end of Roman rule, but this is unlikely. It is probably a folk-memory of the autonomy granted Dumnonian aristocrats, especially as Roman power waned in Britain.

The years between the final days of Roman Britain and the Anglo-Saxon take-over of Britain are mostly lost to time, wars, and the general decline in education during the British “Dark Ages”. We can only guess at what happened, but there are clues, as I discuss in this article about what arose from the remains of Roman Britain. I suspect that Dumnonia was one of the first kingdoms to break away from the Roman provinces at the end of the Roman occupation.

South Cadbury Castle in the 5th Century. Possibly the origin of Arthur’s ‘Camelot’.

What we do know suggests that Dumnonia had strong ties to the British kingdoms in what would become Wales, as well as British colonies in what would become Brittany, in France (the subject of my next blog post). Evidence suggests it was a rich, powerful kingdom. A massive refortification of the Iron Age fort at South Cadbury Castle (the best candidate for “Camelot”) in the late 5th century required a tremendous amount of resources and management. During the same period, the remains of vast amounts of luxury goods from the eastern Mediterranean found at sites such as Tintagel and South Cadbury Castle reflect a boom in trade during the time when Arthur most likely lived.

The Anglo-Saxon tide chipped away at the British kingdoms, however. About 577 AD, Ceawlin, king of Wessex, defeated the Britons at the the Battle of Deorham, capturing the cities of Cirencester, Gloucester, and Bath. This expanded Wessex to the Severn and cut Dumnonia off from the British kingdoms of what would become Wales. This is really the beginning of Anglo-Saxon Britain. The separation was severe enough that it caused the Celtic Brittonic language to begin diverging into Welsh and Cornish.

Dumnonia resisted Anglo-Saxon expansion until the early 9th century. Wessex would continue to whittle away at Dumnonia until only Cornwall remained, probably as a client state to Wessex. The English name ‘Cornwall’ comes from a combination of the British tribal name ‘Cornovii’ with the Anglo-Saxon word ‘wealas’, meaning ‘foreigner’ or ‘slave’. The last recorded king of Cornwall, Donyarth, drowned in 875. Records in Ireland say it was an execution for his collaboration with the Vikings against Alfred the Great. Despite all, Cornwall maintains its own special difference within the cultures of modern Britain.

Dumnonia plays an important role in my Arthurian series. Book 3, Three Wicked Revelations, is currently in production and will explore more of this fascinating kingdom. Thanks for coming by, and as always, I love to hear from you in comments or email.

6 thoughts on “Mighty Dumnonia: Dark Age Politics, Part 12”

  1. It was fascinating to learn that the Cornish and Welsh languages/cultures diverged, but yet were preserved due to (and despite) the eventual Saxon incursions and rise of Alfred. Looking forward to your third book in the series!

    • Thanks, Vicki! Yes, Cornish and Welsh diverged, but they were not the only Brittonic languages to develop from these splinterings of British regions. Cumbric evolved in Northern Britain until it became extinct about the 12th century with the end of the kingdom of Strathclyde (Alt Clut in my novels). The other is Breton, spoken in Brittany, which is the subject of my next post.

  2. By Deorham I am not sure that you can speak only of Saxons, Angles are further North, by then many relationships would have been created with Britons. Britons are mentioned specifically in the AS Chronicle as distinct from Wealas. There is evidence from the Thames Valley of this. Reading Museum has a spear of a mix of British and Saxon work. Sadly, although it is identified as being in their collection they were unable to find it for me about twenty years ago.

    • You’re right, I was using the term very generally, as most people would glaze over if I dove into the minutia. I’m hoping to give some broad overviews and if it inspires people to look more deeply, all the better!


Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.