The dominant paternal lineage of Western Europe
R1b is the most common Y-chromosome haplogroup in Western Europe, and in parts of the Atlantic fringe it accounts for the substantial majority of men tested. It is defined by the marker M343, though nearly all European R1b belongs to the much younger branch R-M269 beneath it. Its modern distribution is strongly clinal, rising steadily from east to west across the continent.
R1b reaches its highest frequencies in Ireland, Wales and the Basque Country, where reported figures often exceed eighty percent of the male population. It remains dominant across France, Britain, the Low Countries and Iberia, declines through central Europe, and becomes comparatively uncommon in the east, where R1a and other lineages take over. Beyond Europe, R1b appears at lower levels in Anatolia and the Near East. A quite separate branch, R-V88, is found in parts of Central Africa, particularly among Chadic-speaking populations — a distribution that is not the result of recent European contact.
The deep origins of R1b lie in western Eurasia, but the branch that matters for most European testers, R-M269, is much younger than the haplogroup as a whole. Ancient DNA has substantially rewritten this picture: R-M269 was largely absent from Neolithic Europe and appears in quantity alongside the movement of steppe-associated populations in the third millennium BCE. Its subsequent spread across the west is closely associated with the Bell Beaker phenomenon, and in Britain that arrival coincides with an almost complete turnover in the male line.
Beneath R-M269, three branches account for most European R1b. R-L21 dominates Ireland, Scotland, Wales and much of western Britain, and is common in Brittany. R-DF27 is concentrated in Iberia and southwestern France. R-U152 is found across the Alpine region, northern Italy and parts of France. Because R1b is so common, the higher-level result is of little genealogical use on its own — nearly everyone with deep Western European paternal ancestry will share it.
For R1b in particular, testing depth matters more than for rarer lineages. Knowing you are R1b, or even R-M269, narrows your paternal origin only to a very large region and a population numbering in the tens of millions. Terminal SNP testing through Big Y or a comparable product places you on a branch that may have formed within the last thousand years, which is the scale at which surnames and parish records start to line up with the genetics.
Live counts by country are shown on this page once the map data loads.