Sauron

Sauron was originally a powerful Maia spirit named Mairon, an apprentice to the Vala Aulë the Smith, who was skilled in craft. He was seduced by the desire for order and control, leading him to Morgoth and becoming his chief lieutenant and servant. After Morgoth's downfall, Sauron sought to dominate Middle-earth, forging the One Ring to control the Rings of Power he had deceived the Elves into making, and after a series of defeats, he was finally destroyed when Frodo cast the One Ring into Mount Doom. Sauron began as a Maia named Mairon, a benevolent spirit serving Aulë the Smith. His desire to impose order and control over everything led him to Melkor, also known as Morgoth, the first Dark Lord. As Morgoth's most trusted servant, Sauron helped in the wars against the Valar during the First Age. After Morgoth was defeated and cast out of the world, Sauron continued his work, aiming to conquer Middle-earth and rule over all creatures. Under the guise of Annatar, the Lord of Gifts, Sauron deceived the Elves of Eregion into helping him forge the Rings of Power. He secretly forged the One Ring in Mount Doom to control the other Rings and, through them, all the peoples of Middle-earth. Sauron's reign of terror was halted when Isildur, son of Elendil, cut the One Ring from his hand at the end of the Second Age. Although his physical form was destroyed, Sauron, connected to the Ring, continued to seek it as his "Great Eye," a fiery, terrifying symbol of his power. Sauron was ultimately defeated when Frodo and Sam destroyed the Ring by casting it into the Crack of Doom, which caused Sauron's shadow to vanish and him to be banished from Middle-earth forever.