Eru Ilúvatar

Eru Ilúvatar was the supreme being of Eä. He was the single creator of existence, all-knowing and all-powerful, and the only entity with the power to create souls. Though the Ainur attempted to shape and govern Eä according to Eru's general will (which they understood imperfectly), he never allowed those who exist within the world to do as they will, and only rarely was known to intervene in the affairs of Eä. Eru was central to parts of The Silmarillion, but was not mentioned by name in Tolkien's most famous works, The Hobbit and The Lord of the Rings, although he was alluded to as "the One" in a part of Appendix A speaking of the downfall of Númenor, and in "Cirion and Eorl and the Friendship of Gondor and Rohan" in Unfinished Tales as "the One who is above all thrones for ever".