Eru Ilúvatar is the supreme deity and creator of all existence in Tolkien's mythology. His name means "The One" or "He that is Alone" (Eru) and "Allfather" (Ilúvatar) in the Elvish language Quenya. Ilúvatar is the singular source of all creation and being, above all other divine entities. He conceived the Ainur, immortal and godlike spirits, through his thought, and through their great music called the Ainulindalë, the universe (Eä) and the world (Arda) came into existence.
Ilúvatar is all-knowing and omnipotent, creating not only the world but also the Children of Ilúvatar — Elves and Men — who have free will. He intervenes rarely and subtly in the world, allowing the Ainur, especially the Valar and Maiar, to govern and shape it. However, his influence can be seen in crucial moments, such as the resurrection of Gandalf and the fate of the One Ring.
The Ainur are the divine spirits created by Ilúvatar to assist in the creation and governance of the world. Among the Ainur are the Valar, the powerful lords and ladies who entered Arda to shape it, and the Maiar, lesser divine beings who serve the Valar. The Ainur are essentially his "offspring" and agents of his will, but none are equal to Ilúvatar himself. Ilúvatar represents the ultimate creative force and the origin of all things in Tolkien's legendarium.
Eönwë - Herald of Manwë, chief of the Maiar.
Ilmarë - Handmaiden of Varda.
Ossë - Maia of coastal waters and storms, servant of Ulmo.
Uinen - Queen of the seas, spouse of Ossë.
Arien - Maia who guides the sun.
Tilion - Maia who guides the moon.
Olórin (Gandalf) - The wisest Maia who became the wizard Gandalf.
Sauron - Originally a Maia of Aulë, later the dark lord under Morgoth.
Melian - Maia who lived in Middle-earth; she married Elu Thingol and they had the daughter Lúthien.
Balrogs - Fiery demonic Maiar corrupted by Morgoth, including Gothmog, their lord.
Manwë - King of the Valar and ruler of the air, wind, and clouds. He is the chief among the Valar and dwells on the summit of Taniquetil.
Varda - Queen of the stars and spouse of Manwë. She created the stars and is revered by Elves.
Ulmo - Lord of waters, master of the seas, lakes, and rivers.
Aulë - The smith and craftsman who created the Dwarves. He governs all things related to crafting and the earth.
Yavanna - Giver of fruits and growth, responsible for all plants and living things that grow from the earth. Spouse of Aulë.
Nienna - Lady of mercy and mourning, teaches endurance and sorrow for the world's suffering.
Námo (Mandos) - Judge of the dead and master of spirits. Keeper of the Houses of the Dead.
Irmo (Lórien) - Master of visions and dreams. Spouse of Mandos.
Tulkas - Champion of the Valar, known for his strength and courage.
Nessa - Lover of dance and speed, spouse of Tulkas.
Oromë - Huntsman of the Valar, associated with forests and hunting.
Vána - Lady of youth and renewal, spouse of Oromë.
Estë - Healer and giver of rest, spouse of Lórien.
Melkor (Morgoth) - Originally the most powerful Vala, turned to evil and became the great enemy.
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