The Tuatha De Danann are the first people of Ireland. They were beings close to humanity, but not a part of it, with the ability to change their shape at will.
While some of the Tuatha De Danann retreated far from humans to become the Daoine Sidhe, other remain on Earth and become the Fenian Heroes and the Heroic Fairies, ladies and knights of classic medieval romances, the heroes of the great tales of the era. By the 11th and 12th centuries, the Heroic Faery had developed to include characters who were fine warriors and champions of the people, as well as patrons of the arts and lovers of cultures.
The Faery Lineage did not stay confined to the shores of Ireland. When the Fenian Heroes found themselves cast adrift from the fiana, they went in search of a new king to serve.
Some tales suggest that they made their way to England and found the legendary King Arthur. Seeing him as a man of honor and integrity, they may have chosen to follow him as they once had the High Kings of Ireland.
It was here, in Britain, that the Fenian Heroes gave birth to the Medieval Fairy.
As followers of King Arthur, the Medieval Fairy are subject of many tales, most of them woven with sorcery and enchantment, wizards and witches, and characters such as Morgan La Fay and Lancelot. Even Arthur himself came to be considered to be one of the fairy people.
IT is also 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 time broad chest and the quivering nostril, and time 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.