J.R.R TOLKIEN'S LEGENDARIUM

Sauron was the greatest and most trusted servant of Morgoth before and during the First Age. After the downfall of his master, he continuously strove to conquer Middle-earth throughout the Second and Third Ages. Deceiving the Elves of Eregion, who under his guidance had created the Rings of Power, he secretly forged the One Ring inMount Doom. Thus Sauron became "The Lord of the Rings".

 

He is also identified as the Necromancer mentioned in Tolkien's earlier novel The Hobbit.