The Rings of Power in the Second Age
About 500 years into the Second Age, Sauron reappeared,[T 17] intent on taking over Middle-earth and ruling it as a God-King.[T 4][T 15][T 21][T 22] To seduce the Elves into his service, Sauron assumed a fair appearance as Annatar, "Lord of Gifts",[T 13] befriended the Elven-smiths of Eregion, led by Celebrimbor, and counselled them in arts and magic. With Sauron's assistance, the Elven-smiths forged the Rings of Power. He then secretly forged the One Ring, to rule all other rings, in the volcanic Mount Doom in Mordor.[T 15] The Elves detected his influence when he put on the One Ring, and removed their Rings. Enraged, Sauron initiated a great war and conquered much of the land west of Anduin. Sauron overran Eregion, killed Celebrimbor, and seized the Seven and the Nine Rings of Power. The Three Rings were saved by the Elves, specifically Gil-galad, Círdan, and Galadriel. Sauron besieged Imladris, battled Khazad-dûm and Lothlórien, and pushed further into Gil-galad's realm. The Elves were saved when a powerful army from Númenor arrived to their aid, defeating Sauron's forces and driving the remnant back to Mordor. Sauron fortified Mordor and completed the Dark Tower of Barad-dûr. He distributed the remaining rings of the Seven and the Nine to lords of Dwarves and Men, respectively. Dwarves proved too resilient to bend to his will, but he enslaved Men as the Nazgûl, his most feared servants. Orcs and Trolls became his servants, along with Easterlings and men of Harad.[T 4]
Downfall of Númenor
Further information: The Silmarillion § Akallabêth
Toward the end of the Second Age, Ar-Pharazôn, king of Númenor, led a massive army to Middle-earth. Sauron surrendered, to corrupt Númenor from within.[T 23][T 3] With the One Ring, Sauron soon dominated the Númenóreans.[T 23] He used his influence to undermine the religion of Númenor, making people worship Melkor with human sacrifice; Sauron was his high priest.[T 3][T 24]
Sauron convinced Ar-Pharazôn to attack Aman by sea to steal immortality from the Valar.[T 3][T 15] The Valar laid down their guardianship of the world and appealed to Eru.[T 3] Eru destroyed the attacking fleet and armies, but also drowned Númenor, which was removed from the physical world, and destroyed Sauron's body, with his ability to appear beautiful.[T 23]
War of the Last Alliance
Led by Elendil, nine ships carrying faithful Númenóreans were saved from the Downfall; they founded the kingdoms of Gondor and Arnor in Middle-earth. Sauron returned to Mordor; Mount Doom again erupted.[T 25] Sauron captured Minas Ithil and destroyed the White Tree; Elendil's son Isildur escaped down the Anduin. Anárion defended Osgiliath and for a time drove Sauron's forces back to the mountains.[T 13] Isildur and Anárion formed an alliance and defeated Sauron at Dagorlad. They invaded Mordor and laid siege to Barad-dûr for seven years. Finally Sauron came out to fight Elendil and Gil-galad face to face.[T 15] When Elendil fell, his sword Narsil broke beneath him. Isildur took up the hilt-shard of Narsil and cut the One Ring from Sauron's hand, vanquishing Sauron. Elrond and Círdan, Gil-galad's lieutenants, urged Isildur to destroy the Ring by casting it into Mount Doom, which would have banished Sauron from Middle-earth for ever, but he refused and kept it for his own.[T 13]
