Emperor Palpatine(Darth Sidious)

Darth Sidious was a human male Dark Lord of the Sith who served as the last Supreme Chancellor of the Galactic Republic and as the Emperor of the Galactic Empire. Sidious, born as Sheev Palpatine, was trained in the dark side of the Force by Darth Plagueis. Eventually, Sidious took on his own apprentice, Darth Maul, and killed his master. As he continued to train Maul, Sidious came into contact with Count Dooku of Serenno, a member of the Jedi Order, who helped further Sidious' plans. In his public persona, Sidious was the unassuming Senator Palpatine of Naboo, a position he used to manipulate galactic events to his own design.

Thirteen years before his Imperial ascent, Sidious engineered theInvasion of Naboo and used the political crisis as a pretext to being elected Supreme Chancellor by the Galactic Senate. With Maul's defeat at the hands of the Jedi, Sidious was in need of a new apprentice. Dooku left the Jedi Order and was bestowed the title "Darth Tyranus" by Sidious. Together, they formed the Confederacy of Independent Systems to spark a galactic civil war. As Chancellor Palpatine, Sidious was given sweeping central, emergency powers to handle the Separatist crisis, and he raised the Grand Army of the Republic to fight the Clone Wars. The clone troopers in the Grand Army had been secretly commissioned by the Sith, and each contained a bio-chip with a preprogrammed protocol to eliminate the Jedi, the sworn enemies of the Sith, when the order was given.

At the war's end, Sidious had gained almost total control over the Republic. With his new power, Sidious branded the Jedi as traitors and ordered the clones to execute Order 66, thus destroying the Jedi Order. With the Jedi destroyed, Sidious declared himself Emperor and transformed the Republic into the Galactic Empire. Sidious also turned Jedi Knight Anakin Skywalker, the Chosen One, to the dark side and anointed him Darth Vader. Over the next several years, Sidious transferred the daily management of the Empire to a Ruling Council and spent much of his time in an ancient Sith shrine beneath the Imperial Palace, attempting to use the dark side to reshape the Force to his own ends.

Meanwhile, the Empire expanded across the galaxy, including the building of the Death Star to maintain order and act as a symbol of fear. However, the Rebel Alliance was formed to resist Sidious' rule, and the Death Star was destroyed by Luke Skywalker. Sidious tasked Vader, Skywalker's father, with either destroying or turning the boy, and Vader ultimately brought Skywalker before his master during theBattle of Endor. There, Sidious attempted to turn Skywalker to the dark side, but Skywalker refused. As Sidious attempted to kill Luke, Vader was redeemed and turned on his master, killing himself and Sidious in the process. Through redemption, Anakin Skywalker destroyed the Sith, while the Rebels successfully destroyed the Death Star II.

Background
Palpatine was born on the planet Naboo and was secretly trained as a Sith Lord by Darth Plagueis before he killed as part of the Sith Code. After many years of training he went undercover as the senator of Naboo, taking a young Dathomirian Zabrak as an apprentice, naming him Darth Maul. He eventually came to the roll of the Chancellor of the Galactic Republic and the leader of the Galactic Senate. After Maul was defeated by Obi-Wan Kenobi, he took Count Dooku, a former Jedi Master, as his second apprentice. Dooku became the political leader of the Confederacy of Independent Systems in the Clone Wars against the Galactic Republic.

Still secretly a Sith Lord, Palpatine was plotting the Republic and the Jedi's downfall. He ended up turning Jedi Knight Anakin Skywalker to the Dark Side and becoming his master giving him the title Darth Vader. Palpatine struck Execute Order 66 on the clone armies forming the Galactic Empire. He set the clones to kill all of the Jedi and most Jedi were killed. Palpatine then became the Emperor of the galaxy and ruler of the Empire along with his new apprentice Darth Vader.

Star Wars Rebels
He made a brief appearance on the Holonet of the Day that Palpatine ended the Clone Wars and founded the Galactic Empire and it was said that on Coruscant Governor Pryce of Lothal was invited for a celebration with Palpatine himself.

Appearances

 * A New Dawn  (Appears in hologram)
 * Star Wars Rebels: Spark of Rebellion  (Mentioned only)
 * "Breaking Ranks"  (Mentioned only)
 * "Empire Day"  (Appears on viewscreen)
 * "Fire Across the Galaxy"  (Mentioned only)

Trivia

 * When Palpatine appears on the viewscreen in "Empire Day", the HoloNet News depicts him as young and handsome instead of his current deformed state, a practice employed by many real-life tyrants using state-run media.