The English are just a collection of German, Danish and French immigrants who killed or enslaved all the celts.
Had to do the opposite of the usual correction this time. There's still plenty of celtic and gaelic peoples in the UK, mostly pushed into the unpleasant mountainous areas that the Angles, Saxons, Vikings and Normans didn't want. Jutes too, I suppose, but they didn't settle much of Britain.
Probably less viking heritage further south too, because of the Danelaw.
There's probably some Norwegian viking descended sorts in Scotland, but I doubt there are too many, who really wants to settle in Wales and Scotland?