It is dominant among males in Ireland, Scotland, Wales and Brittany, present in high frequencies in England and western France and present also to a lesser extent in Iberia, Scandinavia and the Low Countries.

[2] This haplogroup first emerges in the Early Bronze Age in Britain and Ireland, where the earliest samples begin to appear.

Its introduction was part of a large genetic transformation associated with the Bell Beaker culture, wherein steppe descended peoples largely replaced Britain's earlier Neolithic population.

[note 1] It later fell to its modern levels in Britain after the Anglo-Saxon invasions.

However, it still remains the dominant lineage in Ireland, Scotland, Brittany and Wales.