After the War of Wrath, the Middle Men were in a primitive state, as they had no contact with the Eldar or the Edain of Beleriand. Some of the Men were taught agriculture by the Entwives, whom they honored. In contrast, the Edain had retreated to the isle of Elenna and flourished, but around S.A. 600 the Númenóreans established contact with the Middle Men of Middle-earth and taught them agriculture, stonecraft and smithying. But it was around S.A. 882 when King Gil-galad warned the Númenóreans that an evil power was taking shape in the East.
Indeed, Sauron, who had denied the judgment of the Valar, established himself to Mordor around S.A. 1000. He fortified the land with the Black Gate and armies of the Men of Darkness whom he corrupted and enslaved. He also built Barad-dûr near Mount Doom.
Sauron attempted to corrupt the prosperous Elves of Eregion persuading them to create the Rings of Power. When the Elves rejected him, they begun a bloody conflict against him, but Sauron destroyed Eregion and devastated much of Eriador, pushing the Elves back to the Blue Mountains, as the Dwarves retreated to Moria. Sauron now dominated most of the Westlands and the East. But then the powerful Númenóreans responded to the Elves' plea and sent ships and armies to their support. The alliance, after heavy fighting, managed to reclaim Eriador and pushed the Dark Lord back to Mordor with a handful of orcs.
However this was not the end of the Dark Days. Sauron directed his power over the far south and east.[source?] Meanwhile Númenor fell under the Shadow and the colonists started to oppress the primitive Men of the Westlands, demanding tribute of goods and wealth. Some indigenous folk of Middle-earth were afraid of those Black Númenóreans, and their ships and intended at some point to conquer the land of Agar and slay its people.
The arrogant Númenóreans started to see Sauron as their competitor, and King Ar-Pharazôn came against him. Sauron was taken on Númenor, further corrupting the Númenóreans, who continued to enslave the primitive Men and even using them as human sacrifices. The corruption eventually resulted to the Downfall of Númenor.
Sauron's spirit escaped to Middle-earth. Sauron returned to Mordor, where he slowly rebuilt his strength. Unable to assume a fair shape, he started to rule through terror and force.
The Faithful who escaped founded Gondor and Arnor in Middle-earth and gathered Mannish peoples under them, including the Men of the Mountains who formerly worshipped Sauron. Sauron still considered the Númenóreans his most hated enemies and he launched a pre-emptive attack against them. The Númenóreans formed a Last Alliance with the Elves of Lindon and fought Sauron in the War of the Last Alliance, where finally Sauron perished.
Sauron's defeat ended the Dark Years and the Second Age, and allowed the Númenórean realms to flourish during the Third Age.
Other names of this period were the Accursed Years, the Days of Flight.
 Portrayal in Adaptations
- Some of the Dark Years are seen during the Prologue to the film accompanied by Galadriel's narration. After Sauron forged the One Ring, his power is seen expanding over a map of the Westlands, with flashback scenes of battles and peoples being ravaged and enslaved by Orcs. The Last Alliance is formed by the Free Peoples as a direct response to Sauron's brutalities.
- ↑ 1.0 1.1 Robert Foster, The Complete Guide to Middle-earth, p. 82
- ↑ J.R.R. Tolkien, The Lord of the Rings, The Two Towers, "Treebeard"
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, "Aldarion and Erendis: The Mariner's Wife"
- ↑ J.R.R. Tolkien, The Lord of the Rings, Appendix A, "The Númenorean Kings", "Númenor"
- ↑ 5.0 5.1 J.R.R. Tolkien, Christopher Tolkien (ed.), The Silmarillion, "Akallabêth: The Downfall of Númenor"
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), The Peoples of Middle-earth, "Tal-Elmar"
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), The Silmarillion, "Of the Rings of Power and the Third Age"
- ↑ Mark Fisher, "Accursed Years: The long years of Isildur's curse" , Encyclopedia of Arda (accessed 19 May 2012)