The Sith Empire was the name shared by a series of empires ruled by the Sith that existed long before the Galactic Empire. The Sith Empires at various moments once controlled most of the galaxy, and often fought against the Galactic Republic and the Jedi Order in a series of wars and battles, including the Great Hyperspace War, the Sith Wars, the Great Scourge of Malachor, the crusade of Krath, and other conflicts, until the last Sith Empire collapsed.
Being of the Sith, the Sith Empires used the dark side of the Force. These governments were built up through the use of slave labor, a practice that the Galactic Republic outlawed during its stewardship of the galaxy. The idea of an enormous, spacefaring, planet-destroying superweapon had dated back a millennium prior to the rise of the Galactic Empire; in the days of the Sith Empire, tyrants were playing with the idea of a weapon so powerful that it could destroy entire worlds. Although only a few superweapons were produced by the Sith Empire, it wasn’t until the successes of Darth Sidious and Darth Tyranus with the outbreak of the Clone Wars that the idea came to fruition in the form of the Death Starbattle station.
The Sith Empire was first identified in Star Warscanon in the 2017 novel Aftermath: Empire’s End by Chuck Wendig. The Sith Empire originated in the Star Wars Legends comic Tales of the Jedi – The Golden Age of the Sith 0 on July 1, 1996.