Well the idea is the King came first. With a retinue of loyal men. And that the settlers came after. In a span of a century or so. Note that in this theory, there was little to no confiscation of lands of the Britons and that the germanics settlers mostly settled on lands left empty by the previous crisis. Not so disimilar to what happened in many other regions elsewhere in West Rome. The only difference is the numbers of migrants. Up to 40% of the new population according to some.
Which is why the Anglo-Saxon assimilated the Celts and not the reverse like elsewhere.
As for other examples, well that's the thing. We don't have any other point of comparison where a culture supplant another so fast.
Which is why the Anglo-Saxon assimilated the Celts and not the reverse like elsewhere.
As for other examples, well that's the thing. We don't have any other point of comparison where a culture supplant another so fast.