Númenor is the island kingdom that sinks in J.R.R. Tolkien’s mythology.
Númenor was created as a homeland for the Men who had aided the Elves during the wars against Morgoth. Its people received an island in the western sea, and their civilization became powerful, wealthy, and long-lived compared with other human kingdoms.
Over time, Númenórean rulers grew resentful of the Elves’ immortality and defied the Ban of the Valar. The final king, Ar-Pharazôn, attempted to challenge the power of the Undying Lands. In Tolkien’s account, this rebellion led to the destruction and drowning of Númenor.
Survivors led by Elendil escaped and founded the kingdoms of Arnor and Gondor in Middle-earth. Númenor therefore connects the ancient mythology of The Silmarillion with the political history seen in The Lord of the Rings.