Oh, tut tut! You've been reading too many histories based on Roman rumour. That is really OLD and OUTDATED stuff.
Read more recent research which shows that most Vikings were farmers in search of additional land for their families as the weather warmed and the Scandinavian population grew but the arable land did not increase. Look how they civilized Ireland, well, at least compared to what it was. And, they were tremendous explorers and adventurers.