Main article: Sauron in the Second Age
Although Sauron long knew than Men were easier to sway, he sought to bring the Elves into his service, as they were far more powerful. So after the War of Wrath, Sauron decided that the Valar had forgotten about Middle-earth and he once again turned to evil. 
After lying hidden and increasing his power in secret, Sauron put on a fair visage, calling himself Annatar, the Lord of Gifts, and in S.A. 1200 he befriended the Elvish smiths of Eregion, counselling them in arts and magic. He never came to Lindon as Elrond and Gil-galad did not trust him and refused to treat with him, although they never realised who he truly was. Elsewhere he was gladly received, especially in Eregion where the Elvish smiths learned much from him as their thirst for knowledge was great.
Under Sauron's tutelage the Gwaith-i-Mírdain, under the leadership of Celebrimbor, grandson of Fëanor, became more skilled than anyone else, save for Fëanor himself. In the year 1500, when they reached the very height of their power, the Elves began the forging of the Rings of Power, but Sauron knew all their secrets and in 1600 - ten years after the completion of the Rings of Power - Sauron created The One Ring to control the bearers of the other Rings.
But the Elves were not so easily ensnared, and as soon as Sauron put on the One Ring they and Celebrimbor were aware of him, and realised they were betrayed. They hid their Rings from Sauron and did not use them. Sauron demanded that the other Rings be given to him, for they would not have been without his knowledge. The Elves refused, and the War of the Elves and Sauron followed.
Portrayal in adaptations
- At an early stage of script development and shooting, Annatar was to be featured in this film. The fair form of Sauron would appear when Aragorn called forth Sauron at the Battle of the Morannon. After blinding everyone, he would change into the black armoured Sauron that appeared in the rest of the film, and battle Aragorn. This idea was scrapped (Aragorn fights a troll instead), but footage was shot, and still exists.
- ↑ 1.0 1.1 1.2 J.R.R. Tolkien, Christopher Tolkien (ed.), The Silmarillion, "Of the Rings of Power and the Third Age"
- ↑ 2.0 2.1 J.R.R. Tolkien, The Lord of the Rings, Appendix B
- ↑ 3.0 3.1 J.R.R. Tolkien, The Lord of the Rings, The Fellowship of the Ring, "The Council of Elrond"
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), The Silmarillion, "Appendix: Elements in Quenya and Sindarin Names", entries anna and tar-
- ↑ Michael Pellerin (director), "From Book To Script: Forging The Final Chapter", The Lord of the Rings: The Return of the King - Special DVD Extended Edition, "The Appendices: The War of the Ring"