The Firbolg are primordial inhabitants, or early gods of Ireland.  They can be compared with the Titans or Olympic Gods of Greece.  The third wave of invaders, they conquered the Formorians and ruled Ireland between 2000 BC and 1000 BC when they in turn were defeated by the Tuatha Dé Danann who mysteriously appeared in the west of the country.

The name appears to mean “bagmen” or “men of the bags”, but could it have something to do with the fire in their bellies, which would also explain why they refused to make peace with the Tuatha Dé Danann despite the apparent superiority of the new invaders weapons.

They were defeated in battle near Cong and driven into the most westerly areas of the country where they became the first fairies of Ireland.