[Reily]

I've read articles by some Irish scholars claiming the “Travelers” are a surviving remnant of the inhabitants of pre-Celtic Ireland.

The Celts invaded the British Isles and were contested by somebody. I doubt its was elves, fairies and leprechauns!

[yarddog]

I am not sure who the earliest inhabitants were but there were Celtic tribes around the time of Christ. Ireland was invaded by a tribe called “Scots” who then settled the islands and eventually went to Scotland where they again fought with native Celts.