J.R.R. Tolkien named the destroyed island kingdom Númenor.
Númenor was an island realm created by the Valar for the Men who had supported the Elves during the wars against Morgoth. Its people became renowned for their long lives, seafaring, and learning. Over time, however, fear of death and resentment toward the immortal peoples of the West led Númenor’s rulers toward rebellion.
The kingdom was destroyed in the Second Age when Ar-Pharazôn attempted to challenge the divine powers of the West. Tolkien described the catastrophe as a massive reshaping of the world, after which the surviving Faithful founded the realms of Arnor and Gondor.
Númenor is sometimes confused with Valinor, the land of the Valar, or with Beleriand, the region destroyed at the end of the First Age. Its downfall is one of Tolkien’s clearest examples of pride, mortality, and the consequences of seeking forbidden power.