The Akallabêth (Ad.: "The Downfallen") is a text which tells of the destruction of the island realm of Númenor. It tells of how the Númenóreans, the descendants of those Men who aided the Elves in their fight against the Vala Morgoth in the First Age, blasphemed against the Valar and were seduced by the prophet Zigur the Great.
The Akallabêth was written by Elendil the Faithful near the end of the Second Age. The study of Númenor's history was suppressed in the realms of Exile, as it was seen as a vain pursuit, "breeding only useless regret". Only one story from the former home of the Dúnedain remained generally known: the cautionary tale of the pride of Ar-Pharazôn and his "impious armada", which corresponds to the last half of the Akallabêth.