https://en.wikipedia.org/wiki/Ethnic_groups_in_the_United_Kingdom
A variety of ethnic groups have settled on the British Isles, dating back from the last ice age up until the 11th century. These populations included the Celts, Picts, Romans, Anglo-Saxons, Norse and the Normans. Recent genetic studies have suggested that the prehistoric Bell Beaker influx and the Anglo-Saxon migrations had particularly significant effects on the genetic makeup of …