At Sauron's urging, Ar Pharazon raised the mightiest fleet (probably of Spell Jammers) ever seen on Arda and assaulted Valinor. The Valar cried out, and Valinor was separated from Arda's sphere, and the Westward Road was sundered: the only major known edit performed directly by Eru Ilùvatar since Arda's creation. Valinor was no longer reachable, and the Island of Numenor sunk beneath the sea.

This corruption founded the line of Black Númenóreans; high men bent to evil ends. The fleet and its crew were mothballed in burial mounds on the beach of the island of the gods, and prophesied to return for Dagor Dagorath. Meanwhile the scattered Black Númenóreans who had not sailed with the fleet or died in the flooding kept their heads down, but re-emerged from time to time to plague Arda. Notable historical locations include Umbar, haven of the Corsairs, and Angamar. Many of the Eastern nations such as Khand and Harad and parts of Rhun remained under the sway of Sauron through the Third Age, and had their own scions of the Black Númenórean line, including some of the nine Kings of men who became the Nazgûl.

Recently Eru told Thalion Paurgiliath Arch Duke of Eltán that the Black Númenóreans are awake and returning, and that we must prepare.