Ainur

The Ainur, or Holy Ones, were primordial spirits and the mightiest beings created by Eru long before the beginning of Middle Earth in the Lord of the Rings Universe.

Fourteen of the Ainur were the powerful Valar who were primordial guides. The fifteenth, Melkor, strayed from the righteous path and became the first Dark Lord. The many lesser Ainur are known as Maiar. Sauron, the second Dark Lord, was a Maia and so was Gandalf the wizard.

Those Ainur who entered the World and chose to live in it at its beginning remain bound to it until its end. They have much knowledge of the World, but are not themselves omniscient.