Always find it odd when people categorically state their ancestry, as it really depends on where or in this case when you stop looking.
There is strong evidence that we are all descendants from people that lived in what is now Africa.
There is the other nail in the coffin, the borders and invisible lines the divide countries just didn't exist if we go far back either.
Lastly, there has been so much interbreeding that genetic traits are barely perceivable, especially within Europeans.
Was talking to a well known Greek archaeologist a few weeks ago, he said he had seen enough evidence to believe that ancient Greeks were mainly blonde with blue eyes.
Being blonde with blue eyes he said i was likely more Greek than my Greek friend, which upset my dark haired, dark eyed Greek friend
What upset him even more was when the archaeologist said that the typical Greek trait of dark hair, dark eyes and dark skin is as a result of the Turkish genetic influence.
For those that have never been to Greece, the Greeks were under Turkish occupation for many years, and Greeks take Turks in a similar regard as English to French only turned up to 11, so this was like a red rag to a bull for my Greek friend.
Still in Afghanistan you can find communities with lighter coloured hair and blue eyes, the theory being they are ancestors from when Alexander the greats troops came through.
The UK is even more a mix, when we say the Romans invaded this doesn't just mean that some folks from Italy rolled up, the Roman army was made of a massive array and mix of ethnicity.
No idea if there is documentation on who ethnic groups were involved in taking the UK, but it wouldn't superior me to read/hear that there were many Greeks, Spanish or even Arabic troops playing a bit of bom chikkiiiii boooowww wooowwww with the locals.