Númenor is the fictional island kingdom destroyed before the events of J.R.R. Tolkien’s The Lord of the Rings.
Númenor was an island kingdom granted to the Men who had aided the Valar during the War of Wrath. Its people became powerful sailors, and their civilization developed a long history of exploration, political conflict, and increasing resentment toward the immortal Elves.
Under King Ar-Pharazôn, Númenor challenged the authority of the Valar and invaded the Undying Lands. In Tolkien’s mythology, this rebellion led to the changing of the world and the destruction of the island in the Downfall of Númenor. Elendil and his sons escaped and later founded the realms of Arnor and Gondor in Middle-earth.
Númenor is sometimes compared with Atlantis because both are legendary islands destroyed by catastrophe. Tolkien’s account, however, belongs to his own mythology and is presented through the history of the Númenóreans. Its destruction explains important ancestry and political history behind The Lord of the Rings.