The English are a Celto-Germanic people. They can trace most of their heritage in Britain back around 4500 years with the Bell beaker migration to Northwest Europe.
The indigenous people of Britain were the Celts. Who are still the majority of the British gene pool.
There is only one group who had any meaningful effect on the population of Britain, and that's the Germanic people.
Ethnic gaslighters will often name as many invasions as possible to confuse the reader. It's extremely dishonest and often goes something like this.
"English? Do you mean Celts? Angles? Saxons? Jutes? Normans? Romans? Vikings? Frisians?"
One of the most annoying things about this is the fact they name the same thing about 5 times.
The Jutes, Angles, Saxons, and Frisians were Anglo-Saxons, mostly coming from Denmark and settled south-eastern England.
The Romans had no effect on the British gene pool so can be immediately dismissed as historical illiteracy.
As for Vikings and Normans, they were both Germanic and pretty much genetically identical to the Anglo-Saxons.
The Normans came from France but they were descended from viking settlers.
To conclude, the only thing you really need to know is that the English are Celto-Germanic. And have remained unchanged for about 1000 years.
This document was originally written by GoS and reposted here as an archive.