The so-called experts don’t even agree on the extent to which Anglo-Saxons displaced or “ethically cleansed” the indigenous population of Britain. I’ve read claims that H. sapiens sapiens interbred with H. sapiens neaderthalensis, and vice versa. We will probably never know the truth.
I thought the Neanderthals retreated to the remote areas, like Scotland - where they survive today.
Which begs the question, has anyone checked the Muslim population for goat DNA?