The Dark Lord of Mordor. Forged the Ruling Ring... the Master Ring... the One Ring... TO RULE THEM ALL!!!

The greatest servant of Morgoth, a creation of Aulë, he went over to the darkness, and was corrupted. in the third age he became the Dark lord of Mordor, otherwise known as the Necromancer, and was destroyed when his ring was cast into mount doom. Is to be revived in the battle of Dagor Dagorath.

Sauron was originally a Maia to Aule. (A maia is a lesser god who is subservient to the greater ones)
He eventually went to the service of Morgoth, and became his lieutenant.

Sauron returned and entered Mordor and erected the tower of Barad-Dur. When the Numenoreans challenged him, he went as a prisoner, and eventually became a trusted advisor. The Numenoreans tried to fight the greater gods and they all died.
Once he came back, he slipped back to his old ways. He aided the Elves in making rings of power, and eventually he made the One Ring, or the Ruling Ring.
Later on, Sauron gave some of the rings of power to men, and eventually they fell under the power of the Ring and became the Nazgul.
The words on the ring are: One ring to bring them all and in the darkness bind them.

The elves and men formed the "last alliance" and went to fight the hosts of Mordor. They laid siege to Mordor. Then Sauron came and killed quite a few elves and men before killing Gil-Galad and Elendil before Isildur cut the Ring from his finger. Barad-Dur was leveled to the ground, but its foundation was not destroyed, because its power was tied with the ruling Ring.

Sauron hid in Mirkwood, and the wizards came from over the sea to challenge Sauron's power. (The wizards are also lesser gods) Sauron eventually went back to Mordor and rebuilt Barad-Dur.
Eventually, Frodo and Sam threw the Ring into Orodruin, or Mount Doom, and the Ring was destroyed and the power of Sauron was diminished forever.

Used to serve Aule but Melkor turned Sauron evil. After Morgoth was sealed away, Sauron became the Dark Lord. Forged the One Ring but eventually was cast into the void like morgoth was when Gollum fell into Orodruin with the Ring.

First a Maia of Aulë, then Melkor's lieutenant, then tyrant of Mordor.

Possibly one of the greatest villains ever. He is also one of the most original (The LOTR has been around before star wars). He's pretty awesome when he sends a bunch of guys flying through the air. Nice armoured suit too. It's a shame you don't see him very often. No one really knows what his face looks like either.

Besides the dark lord of LOTR, this term can be used to describe a person or situation that is unpleasant or annoying or just messed up.

middle earth's equivalent of a crack dealer.

This is a name in the J.R.R. Tolkien series, Lord of the Rings. Sauron was the Villain in the LOTR's and he caused great evil to come about. he was formally the Luitenent to Melkor the Enemy, and is a half-god.

Also Sauron was a character in X-men and he was Pteradactol man mutant. He was a great mutant that could somewhat take mutant's powers.