Uh huh, and what constitutes a 'distinct group'? What distinguishes one group from another?
The Vikings, when they first arrived in countries Russia, France, Greece, England, Ireland, were distinguished primarily by their tendency to brutally attack the native populations of those lands after embarking from their distinctive dragon prowed ships, wearing their distinctive armor, carrying their distinctive axes, loot their houses, carry them off into slavery and the like. They were also distinguished by their language.
You're trying to make me say something like "skin color" aren't you? Here are two famous native inhabitants of the British Isles:
. Tom's obviously been spending a great deal of time in the sun and doesn't look exactly nordic does he?