Leastwise that's been my understanding from our history as portrayed in the King Arthur stories.
Interesting that this genetic study demonstrates their truthfulness.
(NOTE: Regarding "King Arthur", that's just the masculine form of "Boudicca" or "Boadicea". Although this name is usually translated as "victorious", it is clearly a phrase made up of "bo" or "bo", "u" or "a" or "au", "dic" and "ca". "Bo" is just another Celtic honorific, as in Mc, Mac and O'. It's not used often these days. "A", "U", or "AU" is clearly a Gaelic name cognate to "Arthur". "Dic" is clearly the root Indo-European for "king" or "queen". "Ca" makes it all feminine, as in "queen".
The "King Arthur" stories might more properly be called "Annals of the Kings of Briton".)
That's interesting. I had a friend with the surname Carvajal. His name was always a mystery to me. I assumed it was Hispanic (I live in Texas), and he did have dark hair and eyes, but he really had no other Hispanic features. I never did ask him about his ethnicity, but it always occured to me that he was a white guy, and not a Spanish white guy either, but more of a northern European.
This answers some questions I had in my mind.
' "Bo" is just another Celtic honorific, '.....
You have solved a mystery for me. In rural areas of the coastal plain of South Carolina, an area populated first by Scots-Irish, then by Highland Scots after the highland clearances, men who are friends often address each other as "Bo". I used to live there, and I haven't heard this anywhere else. You don't hear this in the city, only in the country. Now I understand.