Darth Sidious, a Force-sensitive human male, was the Dark Lord of the Sith who founded the Galactic Empire after toppling its predecessor, the Galactic Republic from within. Prior to his term as Supreme Chancellor and subsequent reign as the Galactic Emperor, Sidious was born approximately eighty-four years before the Battle of Yavin and given the name Sheev Palpatine during the Age of the Republic. A native of the Mid-Rim planet Naboo, Palpatine pursued a career in politics and eventually became his homeworld's representative in the Galactic Senate. Although he cultivated the persona of an honest and trustworthy public servant, SenatorPalpatine was an ambitious Sith Lord who learned the ways of the dark side of the Force during his secret apprenticeship under Darth Plagueis. Following in a lineage of Dark Lords that began with Darth Bane, who reformed the Sith a millennium prior to the Fall of the Republic, Sidious spent years conspiring to restore his Order to galactic dominance. After killing his Sith Master, he trained an apprentice of his own, the Dathomirian assassin Darth Maul in accordance with the Rule of Two—Bane's decree that there should only be two Sith Lords at any given time.
In 32 BBY the Trade Federation invaded Naboo under Sidious' orders. Using the situation to his advantage, he manipulated his monarch, Queen Padmé Amidala into leading the Senate to removeChancellor Finis Valorum from office, thereby enabling Palpatine to replace him as the next and last Supreme Chancellor of the Republic. Despite the loss of his apprentice during the Battle of Naboo, Sidious' plans proceeded apace with the aid of Maul's replacement—the fallen Jedi Master Count Dooku, who assumed the name of DarthTyranus after turning away from the Jedi Order he once served. Together, Master and apprentice engineered a secessionist movement that tore the thousand-year democratic union asunder, leaving the galaxy divided and on the brink of war between the Republic and the newly-formed Confederacy of Independent Systems. Hence, in 22 BBY the galaxy fell into a state open war for the first time since the formation of the Republic. Having masterminded the conflict, Sidious was able to control both governments throughout the Clone Wars. Near the war's end in 19 BBY, several members of the Jedi High Council moved to arrest the Chancellor upon discovering his true identity as the Dark Lord. The attempt ultimately failed, however, due to the Jedi Knight Anakin Skywalker, whom Sidious influenced into betraying the Jedi. Replacing the late Tyranus with Skywalker, who adopted the name of Darth Vader as Sidious' third and final apprentice, the Sith Lords initiated Order 66 and, therefore, began a systematic purge that all but annihilated the Jedi Order.
After the fall of the Jedi, the Clone Wars ended with Sidious' ascension as Emperor of the First Galactic Empire. Under the New Order program, the last vestiges of the Republic gradually disappeared. In 0 BBY the Emperor formally disbanded the Imperial Senate and would henceforth rule by delegating authority to an upper cadre of regional governors known as Moffs, such as Grand Moff Wilhuff Tarkin. Shortly afterward, however, the Death Star—a moon-sized battle station with the capacity to obliterate entire planets—was destroyed by the Alliance to Restore the Republic in the Battle of Yavin. As the galaxy fell into another state of all-out war, known as the Galactic Civil War, the Emperor tasked his apprentice to hunt down and eradicate the Rebels, all the while constructing a second Death Star in the Endor system. Despite the challenge to his reign, Sidious grew increasingly occupied by his fascination with the Unknown Regions and, therefore, commissioned the exploration of that vast region of space. By then, Sidious also learned that Vader sired a son, Luke Skywalker, who trained to become a Jedi Knight like his father before him. Sensing an opportunity to replace his hobbleddisciple with a younger and stronger pupil, Sidious tried to turn the aspiring Jedi to the dark side and even manipulated him into dueling with Vader during the Battle of Endor in 4 ABY. However, in failing to turn Skywalker from the light side of the Force, he unleashed the power of the dark side by torturing the young Jedi with a barrage of Force lightning. But the agony he inflicted on his apprentice's son caused the former Anakin Skywalker to overthrow his dark Master at the cost of his own life, resulting in the complete destruction of the Sith as foretold in the prophecy of the Chosen One.
While Sidious had been defeated, the Empire would attempt to maintain the charade of his survival, while struggling to fill the void left by his absence. But Sidious had never intended to be replaced. Prior to the his demise, he created the Contingency to destroy the Empire in the event of his death, believing that the Empire did not deserve to survive without its Emperor. As a consequence, the Imperial remnants were further weakened and less able to resist the New Republic during the waning days of the Galactic Civil War. Ultimately, the Empire capitulated the war after the Battle of Jakku in 5 ABY, ending the era founded by Darth Sidious. Following his death, Sidious' legacy became the base of what became the First Order, an hermit state led by Supreme Leader Snoke, who was also a practitioner of the dark side of the Force. The reign of Snoke would untimely end with his death at the hands of his own apprentice and Skywalker's grandson Kylo Ren, who succeeded his master as the new Supreme Leader, desiring to let the past die along the Jedi and the Sith.