The Galactic Empire

The Galactic Empire, also known as the First Galactic Empire, the New Order, or simply the Empire, is a fascist galactic government that replaced the Galactic Republic in the aftermath of the Clone Wars.

Secretly ruled by Dark Lord of the Sith Darth Sidious—publicly known as Galactic Emperor Palpatine—the new regime rose to power with a groundswell of populist support, promising peace and stability from the destructive Clone Wars and capitalizing on anti-Jedi and anti-droid sentiment. The subsequent Age of the Empire would last only two decades in contrast to the centuries of the Republic Era, but not before the Jedi Order was systematically purged and almost eradicated, and the galaxy largely conquered.

The Empire stood virtually unchallenged until numerous insurgent cells united to form the Alliance to Restore the Republic in 11 BBY.

Great Jedi Purge
As the war neared its end in 19 BBY, the Jedi Order had grown skeptical about the Chancellor after his accumulation of emergency power. They began to suspect that a plot to destroy the Jedi was close to fruition. The ruling council started discussing forcibly removing Palpatine from office and temporarily overseeing the Senate in order to maintain political stability during the transition period. However, the Jedi learned of Palpatine's true identity as Dark Lord of the Sith, Darth Sidious. Following an attempt to arrest him, a brief but vicious fight ensued in which Sidious killed several Jedi and was himself visibly injured. The intercession of Jedi Knight Anakin Skywalker, who was a personal friend of Chancellor Palpatine and already disillusioned with both the Order and the war, ensured Sidious' victory. The prodigal Jedi was turned to the dark side of the Force, while Sidious had a pretext upon which to turn the Republic against the Jedi.

Darth Sidious immediately purged the Jedi Order, issuing to the clone army Order 66: to exterminate all Jedi. With this command programmed into the clones since their births on Kamino, the clone troopers immediately turned on their Jedi commanders and exterminated the vast majority of the Jedi Order in an instant. Meanwhile, Anakin Skywalker—rechristened as Sidious's new Sith apprentice Darth Vader—attacked the Jedi Temple and wiped out what remained of the Order.

However, certain Jedi survived the initial purge, such as Grand Master Yoda, Skywalker's former Jedi Master Obi-Wan Kenobi, Masters Selrahc Eluos, Kirak Infil'a, Coleman Kcaj, Ka-Moon Kholi, Oppo Rancisis, Quinlan Vos, Luminara Unduli and Uvell, former Master Eeth Koth, Chief Librarian Jocasta Nu, Knights Zubain Ankonori, Khandra, Mususiel and Nuhj, Skywalker's former Padawan Ahsoka Tano, as well as Padawans Ferren Barr, Caleb Dume and Cal Kestis. Many of them went into hiding after Yoda and Kenobi fought their way into the Temple and transmitted a holographic message warning the other Jedi about the Republic trap waiting for them there, right before the two Masters failed to destroy the Sith and headed into exile themselves.

Some of them, however, were initially found and either turned to the dark side—as members of an agency of dark side adepts which later became known as the Inquisitorius before being tasked by Sidious with hunting down and destroying the remaining Jedi—or taken prisoner, as Unduli was within the Spire on Stygeon Prime until her execution, after which her remains were preserved by the Inquisitorius to lure other Jedi to their fate.