Sauron ( /ˈsaʊərɒn/) is the primary antagonist and titular character of J. R. R. Tolkien's The Lord of the Rings.
In the same work, he is revealed to be the same character as the Necromancer from Tolkien's earlier novel The Hobbit. In Tolkien's The Silmarillion (published posthumously by Tolkien's son Christopher Tolkien), he is also revealed to have been the chief lieutenant of the first Dark Lord, Morgoth. Tolkien noted that the "angelic" powers of his constructed myth "were capable of many degrees of error and failing", but by far the worst was "the absolute Satanic rebellion and evil of Morgoth and his satellite Sauron."
Read more about Sauron: Names and Titles, Appearance, Concept and Creation, Adaptations, Allusions in Other Works