Galactic Empire

The Galactic Empire is a powerful and corrupt intergalactic faction that rules the Star Wars galaxy and was founded by Emperor Palpatine. The Empire formed after Order 66 was executed, where Palpatine changed the Galatic Republic into the Galactic Empire. They ruled most of the Galaxy until they were defeated and overthrown by the Rebel Alliance with the help of Luke Skywalker, Princess Leia, and Han Solo. The remnants of the organization would later form the Imperial Remnant.

Galactic Empire
The First Galactic Empire was founded during the end of the Clone Wars, when Palpatine tricked the galaxy into thinking the Jedi had tried to overthrow him. To ensure "Peace and security" to the Galaxy, the Republic was reorganized into an oppressive Empire based on tyranny, brutality, and hatred of non-humans. Aliens were not only persecuted, but enslaved to serve the Empire. Funds were diverted from social programs into a massive military buildup, most notably the Stormtroopers. The Empire was also the creator of the Death Star, which they used to destroy Alderaan.

The Empire was later defeated thanks to the destruction of their second Death Star, and the death of Emperor Palpatine at the hands of Darth Vader. The rest of the imperial forces were defeated by the New Republic after attempting a final stand at the planet Jakku. This did not fully mark the end of the Empire however, as the remnants of it would later form the First Order.

Imperial Remnant
The deaths of Emperor Palpatine and Darth Vader, caused the downfall of the Empire, as Palpatine did not plan for succession of rule. Various imperial figures became warlords in an attempt to claim the Empire for themselves, while the rebels grew into the New Republic. By the time the Empire had been restructured, it's economy was weak, and it only ruled a small handful of planets, reducing the Empire to the Imperial Remnant. The Remnant signed a peace treaty with the New Republic ending the Galactic Civil War. The Remnant was not a dictatorship, but a confederacy that did not enlist in xenophobia or slavery as the Galactic Empire historically had. When the Yuuzhan Vong invaded the Galaxy, the Remnant fought alongside with the New Republic and defeated the invaders.

Fel Empire
When Jagged Fel became the Head of State for the Imperial Remnant, the Remnant began to grow once more. Eventually the Remnant was once again an Empire, but the new Empire was quite sympathetic. Aliens were treated just as humans were treated, funds went to social programs and it's military protected the innocent. It even trained it's own branch of Force sensitives, the Imperial Knights. At the same time, the One Sith lead by Darth Krayt began manipulating events throughout the Galaxy. They sabatouged the oassus recovery project, which would help worlds devastated by the Yuuzhan Vong. The Galactic Alliance blamed the vong and soon the Alliance was in chaos. As the Galactic Alliance threatened the lives of the people of the Fel Empire, the Empire reluctantly declared war on it's former ally. The Fel Empire emerged victorious and briefly ruled the Galaxy.

Darth Krayt's Galactic Empire and Empire-in Exhile
The reign of the Fel Empire was short. Darth Krayt staged a coup against Emperor Roan Fel and crowned himself Emperor. The Fel Empire then became Darth Krayt's Galactic Empire. Emperor Krayt waged a genocidel war against the planet Mon Calamari. This rendered the planet was uninhabitable, and millions of life-forms became extinct. But Roan Fel was not dead and formed the Empire-in-Exile, a rebel faction determined to restore the Glory of the Fel Empire. They were joined by the Alliance Remnent, another rebel faction determined to restore the Galactic Alliance. After a long war, the two factions emerged victorious, but Fel died in the final battle (He fell to the Dark Side and was killed by Antares Draco). In the end, the Empire merged with the Alliance and the Jedi Order to form the Galactic Federation Triumverate, a peaceful government that united every single planet in the galaxy.

Military
The Galactic Empire's Imperial Army was the successor of the Republic Military was responsible for carrying out military operations and maintaining control over the Empire's Planets and outposts. It is divided into four sections.
 * Imperial Army
 * Imperial Navy
 * Imperial Military Police
 * Stormtrooper Corps

Trivia

 * The Galactic Empire was primarily based on America during the Vietnam War, with Palpatine specifically being based on then-President Richard Milhous Nixon. Elements of the Roman Empire, Nazi Germany, and the USSR were also thrown into the mix.