My people came from Ireland (specifically a region that was heavily raided and invaded by Vikings), but a couple family members have done a few of those DNA tests over the last few years, and the tests consistently show a strong amount of Scandanavian. A couple of the tests narrowed it down specifically to Norwegian (not sure how that works, but I digress).
For those not in the know, generally speaking in the Viking Age the Danes invaded England and the Norwegians invaded Ireland.
It's not a slamdunk (I suppose a devilishly handsome Norwegian fisherman could have washed up in my ancestral village anytime between the Viking age and the early 1800's and added some Norwegian to my line), but considering that my people came from a region that saw strong Norse influence, I cherish the idea that I am part "Viking."
The Vikings founded Dublin.