Did the English kill off the British?

Were one million or more Britons wiped out by the English in a Dark Ages holocaust?

The place name evidence is unequivocal : there is a very noticeable absence of Brythonic place names in England, especially in the south and the east. In addition, the English lexicon has very few words borrowed from Brythonic languages. 

In the  foundation story of the English nation, the Angles, Saxons and Jutes invaded and settled England from the 5th century onwards, following in the footsteps of Hengist and Horsa who originally brought their mercenary armies to serve Vortigern, the British chief. 

A few centuries later and there is a total cultural transformation. Everyone speaks English and everyone claims to be descended from the original immigrants. 

And what’s more, the modern genetic evidence supports this. 

DNA research has highlighted strong resemblances between Y chromosome haplotypes in Central England and Friesland, an established source of 5th century migrants, which contrast with  genetic samples taken in North Wales. More than 50% of English males today are descendants of Anglo-Saxon immigrants. This genetic evidence suggests an immigration into Central, Southern and Eastern England large enough to replace 50% of the existing male population in a total population of nearly 4 m.
How can we explain the missing million Britons?

The first solution is that there was a mass immigration of Angles, Saxons and Jutes who displaced the native Britons by slaughter, massacre and expropriation. The Britons were forced to flee westwards (to Wessex and Cornwall) or across the seas (to Brittany) as refugees. This explains the concentration of Celtic elements in the South and the West and their complete eradication in the East. 

The second approach, and one which has parallels elsewhere, is to assume a much smaller band of immigrants and to see them as a cultural, political and military élite imposing  themselves, a language and a way of life on the hapless locals. The result over several generations was a cultural and linguistic takeover with the Anglo-Saxons calling all the shots.

The third explanation, currently the most popular, suggests an apartheid structure which systematically excluded Brits and deprived them of their economic, legal and social status. This would, at same same time, have diminished their chances of finding wives and having children. In effect, Anglo-Saxon males crowded out British males in the modern gene pool. This is what is recorded in the DNA which points to a much higher Y chromosome contribution from Anglo-Saxon immigrants than Britons in modern England.

So, there was no mass murder, no genocide, no large-scale exodus and no Trail of Tears. Simply a racial segregation in the East which ensured the decimation of British genes and the forced assimilation of the people. But the ‘conquest’ was drawn out over a few centuries. Wales and Cornwall remained aloof and it is unlikely that parts of Wessex including south Dorset and most of Devon were assimilated until the 7^th or 8^th centuries.

The story also tells us something about Breton place-names. Because the Western Seaways had united Wales, Wessex and Brittany for centuries it is unlikely that the Romano-Gauls in Post-Roman Brittany viewed the incoming Britons as anything other than cousins. When the Roman Empire fell, the eastern sea and land corridors were closed up, and the Atlantic opened up again as the main communications route: for saints, toponyms and settlers as much as for wine and tin.