, after lying hidden and dormant for about 1000 years, Sauron reappeared. Having assumed a beautiful appearance and calling himself Annatar, "the Lord of Gifts", Sauron befriended the Elven-smiths of Eregion, and counselled them in arts and magic. Some of the Elves distrusted him, especially the Lady Galadriel in Lórien and Gil-galad, the High King of the Noldor; the elves in Eregion did not heed their warnings, however.
With Sauron's assistance, the Elven-smiths forged the Rings of Power, which conferred great power to their bearers. Unbeknownst to them, Sauron had secretly forged a master-Ring, the One Ring, in the fires of the volcanic Mount Doom in Mordor. This "One Ring to rule them all" had the power to dominate the other Rings and enslave their wearers to Sauron's will. But the Rings of Power were extremely potent, and to accomplish his goal Sauron was forced to place the greater part of his native power into it. Anyone of sufficiently strong will who possessed the One Ring had available to him much of Sauron's own power to dominate, and should the One Ring ever be destroyed Sauron would be reduced and forever unable to take any physical form.
When Sauron put on the One Ring and tried to dominate the Elves, they became aware of his intent and removed their Rings. Sauron responded with military force, initiating the War of the Elves and Sauron and conquering much of the land west of Anduin. This was the beginning of the Dark Years. He laid waste to Eregion, killed Celebrimbor, leader of the Elven-smiths, and seized sixteen Great Rings, previously forged with his assistance. However, Celebrimbor had forged three Rings himself without Sauron's help, and these were saved and remained in the hands of the Elves Specifically: (according to The Lord of the Rings) Gil-galad (who entrusted Vilya to his lieutenant Elrond), Galadriel, and Círdan (who later entrusted Narya to Gandalf). Note that Unfinished Tales and The Lord of the Rings differ on this point (see article Three Rings).
With the Elves near incapacitated, Sauron proceeded to besiege Imladris, battle with Moria and Lórien, and push further into Gil-galad's realm. The Elves fought back, however, and with the aid of a powerful army from Númenor under their king Tar-Minastir, destroyed Sauron's army and drove it back to Mordor. The Númenóreans held the most powerful kingdom of men at this time; they were descended from the Three Houses of the Edain who had helped the Elves in their war against Morgoth, and they lived on the island of Númenor in the seas between Middle-earth and Valinor.
