The Exegol system, a solitary and remote star system, resided within the uncharted expanses of the Unknown Regions in the galaxy. Exegol, the star at the heart of this system, was orbited by the planet also named Exegol, an age-old world deeply connected to the Sith.
Within his citadel on Exegol, Darth Sidious, a Sith Master, maintained a cloning operation, where the devoted Sith cultists of his Sith Eternal were both guided and educated. For many years, the adherents of the Dark Lord of the Sith labored discreetly, building a Sith fleet known as the Final Order. This armada was ultimately created on Exegol for Kylo Ren to inherit, serving as the next iteration after the First Order.
The ultimate defeat of Sidious transpired on Exegol as well, during the Battle of Exegol, when his granddaughter, Rey, brought about his end.