Melkor

Melkor, later called Morgoth, is a central figure in Tolkien's legendarium. An Ainur, he was the mightiest of the Valar before his rebellion against Ilúvatar. In the Music of the Ainur, he introduced discord and sought to bend creation to his own will, opposing the plan of the Valar. His pride and malice set the template for much of Middle-earth's evil.

During the shaping of Arda, Melkor fought the Valar and corrupted many beings. He destroyed the Two Lamps of Valinor, Illuin and Ormal, plunging the world into darkness. He established fortresses in Utumno and Angband and bred evils such as orcs and dragons. He opposed the Elves and Men for ages, waging continuous wars from the north.

His most enduring crime was the theft of the Silmarils, the magical jewels wrought by Fëanor that captured the light of the Trees. By stealing them, he provoked the Wars of Beleriand and the oath-bound feuds that followed. This act sealed his status as the era's chief antagonist and solidified his dominion over Angband.

At the end of the First Age, the Valar and their allies conquered his realm in the War of Wrath. Morgoth was cast into the Void, his power broken. His defeat did not end the threat, however, as Sauron, his chief servant, carried forward Morgoth's legacy in later ages.