What would you expect with all of that raping and pillaging from Byzantium to Vinland?
Yeah, they spread their own DNA around that way. :^) There has been a recent-years attempt to paint the Vikings as misunderstood bringers of culture. :^)
Then there were the Normans, who were Vikings who settled in northern France, intermarried with the French women, and later invaded England and became the British aristocracy.
They also set up colonies in Sicily and elsewhere in the Mediterranean.
Don't forget about the Vikings' rich and diverse cultural exchange program... AKA slavery.