Darth Sidious

Early life
Hailing from the planet Naboo, Palpatine's rise to power began with the Battle of Naboo. He wielded the power of the dark side of the Force believed to emanate from a so-called Dark World in the Unknown Regions, a mythic location taught to him by his own mentor, Darth Plagueis.

Chancellor of the Republic
Before becoming Emperor, he succeeded Valorum as Chancellor of the Republic.

Anakin Skywalker succumbed to the Emperor's temptations.

Birth of the New Order
"I don't think the Emperor was exactly thinking about what we've just done when he was handing out his reformation acts." "The shriveled old man wouldn't even know that lekku can be used that way."

- Hera Syndulla and Kanan Jarrus

As Emperor, Palpatine established his New Order and the Imperial regime of the Galactic Empire at the end of the Clone Wars. The Emperor claimed the Jedi were planning rebellion, although they were too few in number to oppose him, and many fell to the Empire and its sinister agents while others fled into hiding after the Jedi Temple was left ruined. The Imperial New Order was enforced by Lord Darth Vader, although the Empire still depended on the Emperor remaining on top. The Emperor and Vader carried out a Jedi Purge.

Palpatine handed out reformation acts, and the iron fist of Imperialization claimed many worlds. Some saw the reformation as a new dawn for the galaxy, to replace the corrupt remnants of the Republic with true peace and justice, although later actions such as the Antar Atrocity proved the Empire was little interested in the rights of its citizens, and the Emperor and his cronies were opposed to the values of the Republic. Spice miners on the moons of Naboo launched into open revolt at the start of the Imperial era, though they were attacked and many sent to Kessel. Because their actions took place over the Emperor's homeworld itself, the leaders of the revolt were executed or enslaved, although one of the chief ringleaders, Mané, was taken as Mas Amedda's concubine on Coruscant. The Emperor's data-purges caused information on worlds such as Rakata Prime to vanish into obscurity, and helped people forget the horrors the Empire carried out. The Emperor himself retained records on strange occurrences, such as an encounter during the Clone Wars between the crew of a Venator-class Star Destroyer and warrior scouts who seemed to exist beyond the Force.

The pursuit of power
"They're called chrysalides. The Emperor had them in his private zoo, in the Deep Core, a world possibly also a colony of this same ancient empire once. Those characteristics come from proximity exposure to the dark side of the Force."

- Kirana Promenti

The Emperor was rumored to spend much of his time studying Jedi relics and Sith tomes in the ancient shrines beneath the Imperial Palace, and carried out arcane studies into the secret of eternal life, the Living Force, and the Cosmic Force by compiling rumors of the Force Planet and Mortis. Retreating from the public, he delegated much of the daily running of the Empire to Mas Amedda, although the Imperial Vizier continued to consult with his master on serious matters. Despite his reforms, the Emperor was unable to dismiss the need for the Imperial Senate or its authority. He maintained a private zoo in the Deep Core, where he kept chrysalide rancors among other beasts exposed to the dark side of the Force.

Civil war
"So... it's as we feared. The Imperial war machine is going beyond anything we even have a context for comprehending. The Emperor won't stop, not even with the Senate overseeing the Starfleet or the campaigns in the Outer Rim. With that kind of power at the Emperor's disposal...."

- Leia Organa

Rebellion against the Empire increased as groups including the crew of the Ghost launched strikes against the Imperial regime, although rumors of a planet-killing battle station suggested resistance to the Emperor's regime would end and his power would become unstoppable. The Emperor's white-armored Imperial stormtroopers fought against the Rebellion during the Galactic Civil War. The Emperor obfusciated Inquisitors seeking to usurp his mastery of the Force by planting numerous false leads towards mythical locations like Ahch-To. As of this time, Kren Blista-Vanee, head of the Galactic Hyperspace Planning Council, served as the Emperor's advisor.

Final confrontation and death
"But you have learned, Luke. In Cloud City, in the Emperor's throne room, in turning away rather than seeking vengeance for your students' murders&mdash;in all of those, you have proven yourself to be the better Jedi&mdash;the better man&mdash;than I."

- The spirit of Anakin Skywalker, to Luke Skywalker

In his final confrontation with Luke Skywalker in his throne room over Endor, the Emperor knew that Luke was powerless to kill either him or Darth Vader without falling to the dark side of the Force, and it was only the actions of Luke's allies that changed galactic history. The Millennium Falcon fired a torpedo that destroyed the second Death Star and killed Vader and the Emperor.

Legacy
"The Emperor believed that the universe beyond the edges of our map was where his power came from. A place he called the 'Dark World' in the Unknown Regions, where the dark side itself emanated from."

- Kirana Promenti

As of Rey's era some thirty years after the Galactic Civil War, the Emperor was long-dead, though was recalled in tales of the Rebellion's heroism and adventure. Testimonies from martyrs of the Church of the Force informed deacons such as Kirana Promenti of the Emperor's pursuit of knowledge of the Dark World, and his activities in the Deep Core.

Emperor is alive
Sheev Palatine will return to fight Rey in last part of the saga.

Physical appearance and biology
The Emperor was characterized as a shriveled old man by Kanan Jarrus, who suggested Palpatine was ignorant of certain sexual acts. He was old and frail as of nineteen years after the Clone Wars, and Leto Borian believed he would soon die.

Personality and traits
"But we can't restore the Republic if we take for allies those whose values are opposed to it as the Emperor and his cronies are. That way will lead only to a system as callous and rancorous as the Empire is now."

- Leia Organa

As Emperor, he became obsessed with the study of Jedi relics, Sith tomes, and rumors of phenomena such as the Force Planet, Mortis, and the Living and Cosmic aspects of the Force, possibly as a means of achieving eternal life. As such, he retreated from public view and delegated day-to-day affairs and the running of his Empire to others. He believed his power came from a so-called Dark World beyond the edges of mapped space, believing it to be a location in the Unknown Regions from which the dark side of the Force emanated. He sought to obfuscate those who would attempt to usurp his mastery of the Force.