Palpatine

Who wouldn't trust this face?

Palpatine of Naboo was the public name of the Sith Lord Darth Sidious. After serving as representative of Naboo in the Galactic Senate for twenty years, he orchestrated a series of events that led to him being elected Supreme Chancellor of the Senate and receiving broad emergency powers to fight the Clone Wars against the Confederacy of Independent Systems. By the end of the war, he had accumulated enough political power to reorganize the Galactic Republic into the Galactic Empire and declare himself Emperor.

Palpatine was apparently trained to use the Force by a Sith Lord named Darth Plagueis. At an unknown time and for unspecified reasons, Palpatine murdered Plagueis in his sleep.

Palpatine is known to have had three apprentices: Darth Maul, Darth Tyranus, and Darth Vader.

Trivia

Palpatine's Sith name is often misspelled as Darth Sideous.