Millennia ago, after they defeated the Darkness with their immense magical powers, the Ancient Fairy warriors were sent to the heavens to guard Fairy World should the Darkness return, becoming the stars in the night sky. When the Darkness returned they were absorbed by it, causing entire constellations to disappear. After Timmy defeated the Darkness, they were restored and returned to Fairy World. They are seen in the celebration of Timmy's triumph.
In Balance of Flour, they were shown fighting against the anti-fairies in a battle that determined the winner's race were to have godchildren. After years of intense war, the fairies and anti-fairies agreed to settle things in a more logical way: an annual bake off!
They are tall humanoid fairies like Jorgen Von Strangle, the Tooth Fairy, and the Fairy Council, and use tall wands like Jorgen, which suggests that Jorgen and the Tooth Fairy may also be Ancient Fairy Warriors.
The Ancient Fairy Warriors becoming stars in the sky in attempts to ward off evil resemble the Mesopotamian deity Anu creating the stars as soldiers to destroy the wicked. Anu himself is identified with the sky and the nearby constellation Draco.