Vikings were in Russia known as Varangians. Their business was coastal sting operations, and they excelled at it.
Being itinerant tribal warriors from the far fringe of Europe, they didn’t have the ambition to build up a distinctive civilization, like the Arabs or the Romans. First when they settled in Northern France, in Kievan Rus and Sicily and blended with local elites, they started to think and act like regular kings and dukes and counts. At this, they were hugely successful, with at least three mighty kingdoms as their lasting legacy.
And yet, it didn’t take many generations for them to disappear completely. What happened?
The fierce Nordic warriors had strong preference for indigenous ladies. They had kids with them and found the entire bunch so irresistibly sweet that they didn’t mind them talking to each other in their MOTHER tongue.
Like mother, like son, as the Jews certainly know. In a couple of generations, assimilation left few traces of the Nordic legacy, wherever they had settled.
Love conquers all, folks!