The People of the British Isles Project developed a new technique to cluster genetically similar peoples, looking at the British with a racial microscope. What they discovered is that the English are some of the most homogenous/genetically boring people in Europe.

The project discovered 53 genetic clusters, five of them just in the Orkneys, and yet the great majority of Englishmen belong to the same big genetic blob. I don’t think there’s another European country of 50+ million people that shows such uniformity.

In the last millennium there have been major population movements from S England to the periphery that has eliminated some of the country’s genetic isolates. One of the best examples are the formerly Scandinavian people of the Wirral peninsula in NW England.

Wirral was settled by Norwegian Vikings led by a warlord exiled from Dublin. In much the same way Danish Vikings created scattered villages with the ending –by in the Danelaw, the Norwegians left an impression on place names in Wirral, with villages with names like “Thingwall”.

When geneticists who sampled Wirral men discovered that they were just boring old Englishmen. But the when the sample was isolated to surnames that date back to 1366 a large Scandinavan Y chromosome was detected comparable to the Orkneys or Shetlands. https://academic.oup.com/mbe/article/25/2/301/1129414

In other words, if you had gone to Wirral in 1500 you might have seen the occasional person with white blond hair, but the English blob ate them up. This likely happened everywhere because the overall contribution of Scandinavian blood in the English is very small (<10%).