Yes, of course there have been numerous migrations to and from Britain over the centuries, but the one I'm concerned with is specifically the Anglo Saxon migration in the early medieval period and how it seems to have both occurred in great enough numbers to leave a sizable linguistic and genetic footprint, yet at the same time small enough numbers to have left what is essentially a negligible footprint in the history and archaeology. I'm just trying to make sense of that discrepancy.

Those were both much later, and in Ireland. I'm specifically talking about England in the early medieval period.

There are a number of theories regarding the Neolithic decline and subsequent Beaker replacement, but most of them revolve around a plague and/or famine wiping out the Neolithic peoples (maybe even the predecessor to the black plague), so it wasn't as much a deliberate replacement but more of a "oh look, free real estate" situation.

Here's a couple sources on that:

https://en.wikipedia.org/wiki/Neolithic_decline

https://www.technologynetworks.com/genomics/news/earliest-strain-of-bubonic-plague-bacteria-identified-in-neolithic-site-350328

https://www.nature.com/articles/d41586-018-07673-7

Population replacements just don't happen without some outside force killing a bunch of people beforehand, or a level of genocide that would make Pol Pot blush. If you have any other examples, I would love to hear them. And I don't mean that to be snarky, I legitimately want to know if there are other historical precedents of a non-disease, non-genocidal population replacement so I can wrap my head around this. Because your earlier point was right. For all intents and purposes, it's as if the Celts never lived in England in the first place. How can that be?

Thanks for writing all that up, I really appreciate it. I remember reading some other theory (I wish I could remember the author) that stated a similar theory to Oosthuizen, which is that some form of embryonic precursor to Old English was introduced to Britain by the Belgae before the Romans even arrived, and that it followed a similar trajectory to the one you suggest. It lied in wait, evolved as a trade language, and then erupted across Britain as North Sea trade overtook Channel trade, eventually becoming the primary language of the mercantile class before spreading both upwards and downwards to the elites and the peasants, respectively. What's strange though is that if it was a trade language, why did it only emerge and gain traction in Britain, and not across the entire North Sea?

Maybe you're right. I just don't understand how that level of replacement could take place at that time period. It just doesn't happen elsewhere in history like it appears to in Britain. The Persians, the Macedonians, the Romans, the Mongols, the Turks, the Magyars, the Vikings, the Arabs, the Normans, the Visigoths, the Lombards, the Franks, none of them so completely and totally wiped out every last genetic, cultural, and linguistic remnant of those that came before them. We don't see this level of population replacement until the European settlement of the New World, and that can mostly be attributed to disease wiping out most of the Native Americans. As far as I know, nobody is suggesting a plague wiped out the Britons, paving the way for Anglo Saxon resettlement, so for the DNA to suggest upwards of 75% replacement just feels unfathomable to me. If it was a genocide, it would have been one of the most successful ones ever conducted in history, which would require a level of organization that the Anglo Saxons probably weren't capable of, and there would almost certainly be more evidence of it. If it wasn't a genocide, then how on earth did they achieve that high of a replacement rate? Maybe we'll get a clearer answer in coming years/decades as they do more studies and have more data to analyze.

Do you have any sources on hand for the material archaeology? Specifically anything that can only be explained by migration instead of just trade?

If all those local Celts were displaced or killed, surely that would pop up in the archaeological record, right? One would expect there to be abandoned settlements and mass graves in England, while new settlements and communities start appearing in Wales and Scotland at around the same time. But we just don't see any of that. Something must be missing. No matter which version of the story you go with, it just doesn't add up.

While I appreciate the kind words, you could make my day even better by giving me a source I could read.

That's really interesting. I wonder why the papacy would do that? How did that benefit them?

I'll check it out, thanks!

The only point you made that I disagree with is point 3. All of the archaeological evidence suggests that the early medieval period of Britain was not dangerous, violent, or even unstable. Quite the contrary in fact. It all seems to suggest that people just kept on living their lives just as they had under the Romans. Not much really changed. All of their civic structures that they inherited from the Romans remained intact, and there was no interruption or change in how the land was occupied or used. There is nothing in the archaeology to indicate marauding bands of Saxons dominating the locals by force or intimidation.

You do make a good point though, just because the migration didn't happen the way Bede describes it doesn't mean it didn't happen at all. It very well may have, but unfortunately we just don't know for certain. All we can do is speculate until new discoveries are made.

That was a good read, thank you! I hope I live long enough to see these questions definitively answered because it's clear that as of right now, SOMETHING is missing. Whether it's a breakthrough in genetic technology, a massive archaeological discovery, a hidden vault of early medieval scrolls unearthed from some church vault, or a revolutionary new way of categorizing and studying languages, I just hope I'm still alive to see it.

I just saw that it has 161 episodes dating back to June 2012. I'll absolutely give it a listen, but this could take a while. Thanks for the recommendation!

I hadn't heard about this, but I definitely want to check it out

There is, but it doesn't seem to be conclusive. Oosthuizen mentions a genetic study that indicates the vast majority of English DNA comes from France rather than around the North Sea, but I do know there are others that support the conventional Germanic migrant theory. Someone else mentioned a new study that just came out a couple weeks ago that I hadn't heard about yet, so I'll have to check that out as well.