The Tuatha-de-Danaan

It is believed by many people that the cave fairies are the remnant of the ancient Tuatha-de-Dananns who once ruled Ireland, but were conquered by the Milesians.

These Tuatha were great necromancers, skilled in all magic, and excellent in all the arts as builders, poets, and musicians. At first the Milesians were going to destroy them utterly, but gradually were so fascinated and captivated by the gifts and power of the Tuatha that they allowed them to remain and to build forts, where they held high festival with music and singing and the chant of the bards. And the breed of horses they reared could not be surpassed in the world—fleet as the wind, with the arched neck and the broad chest and the quivering nostril, and the large eye that showed they were made of fire and flame, and not of dull, heavy earth. And the Tuatha made stables for them in the great caves of the hills, and they were shod with silver and had golden bridles, and never a slave was allowed to ride them. A splendid sight was the cavalcade of the Tuatha-de-Danann knights. Seven-score steeds, each with a jewel on his forehead like a star, and seven-score horsemen, all the sons of kings, in their green mantles fringed with gold, and golden helmets on their head, and golden greaves on their limbs, and each knight having in his hand a golden spear.

And so they lived for a hundred years and more, for by their enchantments they could resist the power of death.