Plague and the Origin of the Anglo-Saxon Kingdoms

It has been observed before that the earliest English kingdoms seem to appear around 550 AD rather close to the date that the Plague of Justinian arrived in Ireland around c. 544. We don’t yet have confirmation that the plague landed in Britain, but the Annals Cambriae does record the death of the great king Maelgwn Gwynedd in 547, according to legend, from the plague. Given that we know the Irish sea trade was active in the sixth century there is no reason to believe that plague didn’t arrive in Britain as well. Yet conclusive proof eludes us because of the legendary quality of the Annals Cambriae for this period and the otherwise lack of sixth century records. It will be up to archaeologists to confirm plague in period remains.

Let’s do a thought experiment.

Hypothesis: Plague contributed to the depopulation of Roman Britain and the rise of the Anglo-Saxon kingdoms.

To test this hypothesis we need to know:

  • How would plague reach Britain?
  • Where would it be coming from?
  • If plague did come to Britain on the 540s where would we expect to find it?
  • What types of evidence would we expect to find?
  • Why did the Anglo-Saxon centers remain out of the major Roman centers like York and London until the arrival of Roman missionaries?

How would the plague reach Britain?

How the plague would arrive is relatively easy. As with everything else, it would come to Britain by sea and arrive in the major ports. Currently the most evidence for continental contact exists along the Irish sea side at Tintagel, Dinas Powys, and Whithorn. We really just don’t know about the east. The bigger cities in the east may have dispersed good more widely so that we don’t have easily recognizable concentrations of goods. Trade is also a very important factor in the sixth century maritime contacts. There is no doubt that the tin of Cornwall was a primary trade good that continued to be mined and traded in the fifth century. Given the late sixth century Frankish contacts with Kent, it is likely that there was some contact across the channel with southern and eastern Britain in the mid sixth century as well, but we don’t have much proof.

Where would the plague be coming from?

Where the plague would be coming from is not as easy to parse. Given the Cornish tin drawing traders into the Irish sea and Mediterranean goods found at Irish sea sites, it is possible that traders were coming directly from the Mediterranean, with or without making significant stops in Gaul. The Irish annals record a direct trajectory from the Mediterranean without extensive records of plague in Gaul along the route. The only Mediterranean trade goods that I can recall hearing about in early Anglo-Saxon graves is some elephant ivory. Contact with the Mediterranean (or lack of it) may well explain a lot of plague’s distribution in the Atlantic Archipelago rather than trade and communication with Gaul.

If plague did come to Britain on the 540s where would we expect to find it?

It follows that we would expect to find plague along the western coast. The late semi-legendary account of Mealgwn Gwynedd’s death of plague in c. 547 in his court at Rhos on Angelesy is certainly along the western coast. Detecting plague otherwise is difficult without mass graves and I don’t necessarily think that most plague victims were buried in mass graves.

The primary port areas in the east are not well-defined for the sixth century but it seems clear that the Thames estuary was a major trade corridor. Likewise the Humber River in the north was probably a major trade corridor. It’s hard to predict where smaller ports would have been, just as its hard to predict what kinds of trade goods would have been going out of the east. We do know that there was Frankish contact with Kent by at least the third quarter of the sixth century, but how extensive it was is unclear.

The looming question here is what happened to the Romano-Britons in the east. Some migrated to the continent but it wasn’t a huge, coordinated, or destabilizing wave of immigration. Although, a slow small-group migration over a century might not be that noticeable in the historical or archaeological record.  Most of those who went to Brittany seem to have come from western Britain rather than the east. We no longer believe that they were massacred as Bede and Gildas claim (or rather as Bede echos Gildas). Most of them surely assimilated into Anglo-Saxon culture. Some may have been sold as slaves by the Anglo-Saxons but again not enough for Britain to have a reputation as a source of slaves (and the slaves  from Britain known in written sources were all Anglo-Saxon — Imma, Balthild, and Gregory the Great’s boys in Rome). I don’t think slaves from Britain were ethnically chosen.  Between small-scale migration, assimilation and the slave trade, Roman culture collapsed in eastern Britain in the sixth century. With the collapse of Roman culture, the demand for Mediterranean goods may just not have been there.

There really isn’t an obvious reason here why the east would be depopulated worse than the west. Indeed there seems every reason for the west to suffer worse than the east. However, the entire former Roman province east and west seems to be sparsely populated so we can’t rule out that the plague did thin out the entire population.

What types of evidence would we expect to find?

Without documentary evidence we are really left with archaeological remains. Mass graves without traumatic injuries are the ideal remains to test for Yersinia pestis. However, not all plague victims are buried in mass graves. Most plague victims are probably buried in single graves or in small groups. The double grave of the woman and girl found in Bavaria may be more like the typical grave outside of the large population centers. This Bavarian grave was apparently a very carefully prepared grave with typical elite grave goods. It wasn’t a hasty burial. There seems to be an assumption that plague did not come to eastern Britain before 664 so I haven’t seen evidence of screening for the plague in sixth century graves.

Other than graves, plague could cause a depopulation without signs of violence. Settlements have been found throughout Britain that show signs of contraction which could be consistent with losses from plague. I’m thinking here of wooden structures built within Roman ruins, or where only a fraction of a Roman site shows signs of continued habitation. Migration away from Britain could cause similar depopulation without signs of violence. In real terms though pandemics (and other causes of depopulation) do leave the survivors vulnerable to violence as neighboring warlords try to take advantage of the situation and survivors begin to fight over remaining resources.

This brings us really back to bioarchaeology. This is just no way to get around massive screening of sixth century graves to get a clear answer to this question. Detection of Yersinia pestis in 1400 year old remains has a very low efficiency coupled with the likelihood that plague intensity is unlikely to have been even over the island means that small scale screening of a few cemeteries will not be sufficient to answer the question.

Why did the Anglo-Saxon centers remain out of the major Roman centers like York and London until the arrival of Roman missionaries?

There have been various hypotheses put forward for why the Anglo-Saxons avoided the major Romano-British centers. Some have thought that they were initially settled outside of the Roman cities so their centers developed away from London, York, Lincoln, etc. This makes some sense for the fifth century but less for the sixth century. Only a few cities in Wessex (Bath, Gloucester) are recorded as falling to the English after a battle in the 570s, if I recall correctly. It could be that they just didn’t like the Roman style of buildings or that they were too difficult to repair and maintain. It makes some sense that Anglo-Saxon warlords would rather make a fresh start with a new Germanic style hall and complex rather than try to repair and maintain the Roman ruins. On the other hand, the Roman centers were accepted sites of power that we would think that English warlords would want to co-opt. An alternative scenario that I don’t really think has been explored is that these Roman cities were deemed unhealthy by the English. Plague will depopulate rural areas along with cities, but cities still tend to take the brunt of any infectious disease.

There isn’t enough information known to really evaluate the hypothesis. The way forward is fairly bleak. We are looking at extensive screening of sixth century graves (single as well multiple graves) and this will require convincing archaeologists to do the screening. Alternatively looking for contact with the Mediterranean may at least indicate which areas to look for plague more extensively. Correlating Mediterranean contact with the Atlantic archipelago as a unit with the Irish annals may allow us to make some predictions on what and where to look.


12 thoughts on “Plague and the Origin of the Anglo-Saxon Kingdoms

  1. Very interesting blog Michelle, and very apt for me to read having just posted a blog on the ‘540 Cosmic/Volcanic Event’.

    1. Yes, I just got around to reading your post. I’ve been saving it in my RSS reader until I had time to go through it carefully. Its an interesting post, though I don’t think that a comet or volcano is the answer. As you say, it would effect everyone pretty much evenly. In fact the land in the west is generally worse farm land and so would be effected by a famine worse than the east?

  2. I don’t think I have to buy this idea completely to see in it the roots of something quite important that I was tugging at in a post at mine a while ago as well. Chris Wickham, among others, argues for an almost total collapse of political order in Britain; I think that this is really only sustainable in eastern Britain, because of the kings like Malegwyn whom we see in the west. But I think the key thing is as you say that the collapse in the west and the beginnings of visible kingdoms in the east appear to go chronologically hand-in-hand. I think that makes perfect sense, really: the power in the land is in the west, it keeps the powers in the east from forming, once the west is in trouble, the east, with its better links to a rising economic zone at the same time as the prestige goods system that has been monopolised in the west is diminishing, is able to expand and is unstoppable. Whether you think that the cause of the collapse in the west is sheer economics or pandemics, I don’t think it’s fanciful to argue that it’s the collapse of power in the west that enables the rise of power in the east. Then, a plague can hit both sides equally, and it’s not necessary that the west somehow suffer more; the east is just in a far better position to rally.

    1. A collapse of power in the west? Its interesting that all of Gildas’ kings are in the west, even though we don’t know of significant English kings in the east yet.

      There is the claim that Vortigern was an ancient king of Powys. I think Powys was probably the dominant 5th to 6th century kingdom/region. The kings of Powys would have held Chester, Wroxter and possibly extended his hegemony over Caerleon or into South Wales. I’ve always thought that Powys probably extended much further into the midlands than it does even under Cynan Garwen. Powys would have been holding the region that later became western Mercia and/or even northern Wessex. Afterall that region of Mercia and Wessex becomes a major power center in later Anglo-Saxon England.

      Without Roman engineers to handle the watershed in the East, that land may not have been worth as much as the drier areas of the west midlands. Perhaps the River Severn and its estuary became the major trade corridor, replacing the Thames. A short overland portage would move goods from the Severn estuary to the headlands of the Thames for distribution. The headlands of the Thames would be near where the Gewisse/Wessex began and Ceawlin became a ‘bretwalda’. A ‘bretwalda’ rising so far west could indeed disrupt the western power structure or be a symptom of it having already fallen. We have to let go of the myth that the Gewisse developed from the coast inward rather than from Germanic federates settled near Gloucester.

      1. Of course, by that time, the eastern part of Powys (which must have sprang from the Cornovii) may have been Pengwern.

        Christopher Gidlow uses archaeological evidence to suggest that the Cornovii and Dobunni may have been in alliance and held quite a bit of power. I don’t know how accurate his information is though.

        1. I don’t know how well the old tribal system carried over to the post-Roman period. How do we know that they were little more than administrative districts in late Roman Britain? Some of them may have become ‘kingdoms’ but it seems to me that city-states perhaps with more or less regional hegemony were more common.

          If we accept that Vortigern was a high king and was based in Powys, he was able to settle mercenaries in Kent. That is a long stretch from Powys.

  3. This absolutely delighted me. The novel I had outlined (a fantasy, or maybe alternate history) before I turned to Hild had, as it’s basic concept, that The Fall of Rome coincided with the Fall of Something Nasty from the Sky–specifically, a rain of otherworld virus that took out centres of population.

    I can’t tell you how pleasing it is to see a similar real-life hypothesis.

    I like the notion of power-shifting. East to west as the climate got wet and drainage fell apart–leading, to, say, lowered agricultural productivity and diseases like malaria. West to east with the advent of plague.

    I’m really enjoying this idea…

    1. If I read Chris Wickham or Richard Hodges correctly, their version is less exciting: people who rely on being able to monopolise the flow of luxury goods for staying in power lose access to those goods, lose their ability to hold armies together and everything disaggregates. But you know, that could be in there too 🙂

      1. The lovely thing about fiction: you can torment your characters with rain and plague and failed crops and loneliness then close the file and enjoy a lovely glass of wine by the fire in good company 🙂

        But my plan with the alt history book was to posit the conditions, then fast forward four hundred years and see what had happened. Reaggregation, but different. A fun thought experiment.

      2. It all falls apart because they can’t pay off their warriors? Where are they supposed to go for better loot? Not to mention that warriors wouldn’t stay to protect their own families land?

        1. Well, that’s it, I presume, they supposedly go home because there’s no living to be made from war as a professional. I would expect banditry, free companies and so on, but this is not my narrative.

Comments are closed.

Blog at

Up ↑