...Historians teach that they are mostly descended from different peoples: the Irish from the Celts and the English from the Anglo-Saxons who invaded from northern Europe and drove the Celts to the country’s western and northern fringes. But geneticists who have tested DNA throughout the British Isles are edging toward a different conclusion. Many are struck by the overall genetic similarities, leading some to claim that both Britain and Ireland have been inhabited for thousands of years by a single people that have remained in the majority, with only minor additions from later invaders like Celts, Romans, Angles, Saxons, Vikings and Normans. The implication that the Irish, English, Scottish and Welsh have a great deal in common with each other, at least from the geneticist’s point of view, seems likely to please no one.A United Kingdom? Maybe
See also Myths of British ancestry
In the words of one well known Basque cultural icon: HA Ha!