From NERC (more at the link):
Human remains dug up from an ancient grave in Oxfordshire add to a growing body of evidence that Britain’s fifth-century transition from Roman to Anglo-Saxon was cultural rather than bloody. … Had there been a mass invasion, the graves would be expected to contain around 20 per cent immigrant remains. But only five per cent of the buried individuals seem to have come from outside the local area.
‘Oxfordshire is quite some distance from the landing point of any invasion, but it seems that there was not a mass invasion everywhere,’ says Millard.
‘The broader question is still open to debate, and we’re still gathering evidence, but our evidence favours a scenario where there was not a wholesale replacement of the population, but a shift in culture.’
The more awareness among the general public that the Germanic tribes weren’t just the bloodthirsty (literally) savages shown in films like the atrocious King Arthur film from 2004, the better. Our ancestors were sophisticated politicians, artists, and artisans as well as brave fighters possessed of a warrior tradition.