Son of the Naboo noble Cosinga, Palpatine grew up to be cruel and filled with rage. His opposition of his father gained him the attention of Darth Plagueis - under the guise of Magister Hego Demask of Demask Holdings. Cosinga learned of his son's relationship with Demask and decided to send Palpatine away somewhere he could no longer contact Demask. However, Palpatine destroyed his entire family and their guards using nothing but the Force. Once this was done, he contacted Plagueis and was apprenticed to him.
Darth Sidious and Palpatine were created by George Lucas, for use in the Star Wars films, and adapted to graphic novels by Dark Horse Comics. His first appearance is in MAD.
In Star Wars fiction, Palpatine is described as a manipulative and ambitious politician, a ruthless emperor, and an evil Sith Lord. The Star Wars Databank describes him as "the supreme ruler of the most powerful tyrannical regime the galaxy had ever witnessed" and Stephen J. Sansweet's Star Wars Encyclopedia calls him "evil incarnate". In A New Hope and The Empire Strikes Back, Darth Vader is depicted as the ultimate Star Wars villain, but as critic James Berardinelli notes, "With the arrival of the Emperor (a gaunt-looking Ian McDiarmid) [in Return of the Jedi], Vader has turned into a second fiddle." Darth Vader himself reminds Moff Jerjerrod, "The Emperor is not as forgiving as I am."
As a Senator, Palpatine is portrayed as "unassuming yet ambitious". In Cloak of Deception, James Luceno writes that Palpatine carefully guards his privacy and "others found his reclusiveness intriguing, as if he led a secret life." Despite this, he has many allies in the government. Luceno writes, "What Palpatine lacked in charisma, he made up for in candor, and it was that directness that had led to his widespread appeal in the senate. ... For in his heart he judged the universe on his own terms, with a clear sense of right and wrong." In Terry Brooks' novelization of The Phantom Menace, Senator Palpatine claims to embrace democratic principles. He tells Queen Amidala, "I promise, Your Majesty, if I am elected Supreme Chancellor, I will restore democracy to the Republic. I will put an end to the corruption that has plagued the Senate." A Visual Dictionary states that he is a self-proclaimed savior.
As Emperor, Palpatine abandons any semblance of democracy. Sansweet states, "His Empire ... was based on tyranny, hatred of nonhumans, brutal and lethal force, and, above all else, constant fear." In Matthew Stover's novelization of Revenge of the Sith, Count Dooku anticipates the coming of the new government: "A government clean, pure, direct: none of the messy scramble for the favor of ignorant rabble and subhuman creatures that made up the Republic he so despised. The government he would serve would be Authority personified. Human authority." The Emperor enforces his will through clandestine, Force-sensitive agents known as the Emperor's Hands. The Star Wars Encyclopedia calls them "the Emperor's eyes and ears throughout the galaxy" who "communicate with him ... through the Force." Prominent Hands include Mara Jade and Roganda Ismaren.
The apprentice of Darth Plagueis, Palpatine is "the most powerful practitioner of the Sith ways in modern times." The comic Sithisis by Derek Thompson, printed in Star Wars: Visionaries (2005), reveals the extent of Darth Sidious' power as he performs a terrifying Sith ritual that manipulates people and places across the galaxy. Palpatine is so powerful that he is able to mask his true identity from the Jedi. In Shatterpoint, Mace Windu remarks to Yoda, "A shame Palpatine can't touch the Force. He might have been a fine Jedi."
The Databank explains that the Force "granted him inhuman dexterity and speed, agility enough to quickly kill three Jedi Masters" in seconds. Palpatine is a master lightsaber duelist and skilled at using Force lightning to attack his opponents. Stover elaborates on the duel between Palpatine and Yoda: "From the shadow of a black wing, a small weapon ... slid into a withered hand and spat a flame-colored blade. When the blades met it was more than Yoda against Palpatine, more the millennia of Sith against the legions of Jedi; this was the expression of the fundamental conflict of the universe itself. Light against dark. Winner take all."During the duel, Yoda realizes, "He had lost before he started."
Stover also states that when fighting Mace Windu, the Jedi Master manages to reflect Palpatine's own Force Lightening back at him using his self-developed fighting style, the Vaapad. Although much the change in his appearance during the Third film is a result of this, almost no explanation is given as to why Palaptine's eyes turned yellow.
According to the Databank and New Essential Guide to Characters, Palpatine possesses great patience and his maneuverings are as a dejarik grandmaster moves pieces on a board.
Palpatine was a master in the art of lightsaber combat, having mastered all lightsaber combat forms and being able to wield them all effectively ambidextrously. Although Palpatine generally had his apprentices or other lackeys fight battles while he coordinated events behind the scenes, Darth Sidious did show efficiency in lightsaber dueling. As he learned every lightsaber form, he simply shifted forms to confuse his enemies or when he was at a disadvantage against their style. Sidious' skill was enough for him to defeat Kit Fisto, Agen Kolar, Saesee Tiin, Yoda, and Luke Skywalker in lightsaber duels and managed to hold his own against Mace Windu, who disarmed him as a result of Vapaad, Shatterpoint, and possibly Anakin Skywalker's arrival.
Darth Sidious was one of the last Sith under Darth Bane's Sith Order. As a result of Bane's Rule of Two, which established that the apprentice of a Dark Lord of the Sith must supersede the master in power, Sidious had accumulated, effectively, 1000 years of hidden study of the dark side from the two-Sith rule lineage and was, as a result, one of the most powerful Force practitioners in the history of the galaxy.
As Darth Sidious killed his master, Darth Plagueis, while Plagueis slept, Sidious decided that he would never make the "mistake" of sleeping for fear of his apprentice betraying him the same way. Supposedly, Palpatine sustained himself merely through meditation and, thus, never required sleep.
Force Lightning was Palpatine's preferred and most often used Force power. He could use Lightning to kill an entire battalion of stormtroopers in one blast, bend Mace Windu's lightsaber back toward his face, and kill Jedi in an instant.
Emperor Palpatine was particularly skilled in Force powers such as Vision, Precognition, Farseeing, Sense, Telepathy, and other clairvoyant and precognitive abilities. This accounted for his mastery in predicting and manipulating events and other beings. Through use of Force Concealment, Palpatine was able to hide his potency in the dark side and his identity as a Dark Lord of the Sith from even the most powerful Jedi Masters of the Order at the time for decades. He managed to invade and conjure dreams in the mind of Luke Skywalker as he slept to haunt him and tempt him to turn to the dark side. Sidious' influence through the dark side was sufficient for him to dominate the minds of the entire population of the planet Byss and force them to succumb to his rule. His Hand, Mara Jade, could receive mental messages and visions from Palpatine across the galaxy, further showcasing the scales at which his powers operated. Sidious's power through the dark side was great enough that he was able to compel thousands or very possibly millions of people on Coruscant to forget having witness the burial of a Star Destroyer, the Lusankya.
The Emperor proved to be a master of Force Speed during his duels with Mace Windu, Kit Fisto, Agen Kolar, and Saesee Tiin, as well as against Grandmaster Yoda and Luke Skywalker. His speed was great enough to overwhelm his opponents in combat, as Tiin and Kolar never had an opportunity to react and Yoda and Luke both lacked the power and skill necessary to match him. Palpatine showed high physical resiliency and strength, on top of his speed, when he withstood the crushing weight of a ton of machinery being dropped on him by Leia and when he survived Galen Marek's Force energy burst.
In addition to controlling and corrupting Byss' populace, Darth Sidious used Force Drain to siphon the life energies of the world for himself. This was, in part, the reason for his choosing Byss as his personal retreat and ordering his Imperial workers to transport billions of beings to the planet.
Emperor Palpatine knew Force Telekinesis and was refined with this power to the degree of casually using several senate pods as projectiles during his duel with Master Yoda.
After having researched on Byss for nearly six years, Palpatine rediscovered an ancient Force power that allowed the user to alter space and time and channel ambient dark side energies by combining anger and will with their Force sensitivity in order to open a wormhole that could send beings to another sector of the galaxy or through time and had such destructive capacity that it could consume entire star fleets or tear the surfaces off planets. Sidious defined this power as his Force Storm and cataloged the secrets behind it in his Dark Side Compendium. These Storms could be generated by Sidious in a matter of seconds and controlled to send across the galaxy to any star system of the Emperor's choosing. They also had magnetic properties that cancelled out the technology aboard ships and dwarfed them in size.
Sidious utilized the arcane art of Sith alchemy to create war beasts, the Chrysalides, and semi-sentient war ships. Presumably, he also applied his Sith magic for the purpose of granting his Dark Side Adepts a level of Force sensitivity that was merely an extension of his own power for their use in his service, although this given power in the Force was minimal, as his Dark Side Adepts were no match for the Jedi.
Darth Sidious was perhaps the most skilled user of the dark side ability Essence Transfer. This power was used by Sith to survive death by projecting their spirits into another body or artifact. Despite ancient Sith needing outside aid through a ceremony or ritual to use Spirit Transference, Sidious was capable of sending his Essence into another body at will, without pre-prepared settings, and even traveled interplanetary distances to reach a host to anchor his consciousness to. Aside from affecting his own consciousness, Emperor Palpatine seemed to be able to alter the spirits of others, as he did to Bevel Lemelisk more than half a dozen time. Essence Transfer, ultimately, made Sidious virtually impossible to kill permanently.
Darth Tyranus (AKA Count Dooku)
Luke Skywalker (Briefly)
"Hands" of the Emperor: