What name did J.R.R. Tolkien give the creator deity in his fictional mythology?

J.R.R. Tolkien named the creator deity in his fictional mythology Eru Ilúvatar.

Eru Ilúvatar is introduced at the beginning of The Silmarillion as the supreme being who creates the Ainur. Through the Ainur’s Great Music, he brings the vision of the world into being and gives independent existence to the created world, Eä.

The name combines two important ideas in Tolkien’s invented languages. “Eru” means “the One,” while “Ilúvatar” is commonly translated as “Father of All.” Eru is therefore not simply another powerful spirit within the mythology; he stands above the Valar, Maiar, Elves, Men, and other created beings.

Manwë and Aulë are Valar, powerful beings who help govern Arda, while Morgoth is a rebellious Vala who becomes the mythology’s principal enemy. Those names are consequently not interchangeable with Eru Ilúvatar.