The Korriban Siege was a conflict that occurred in the early days of the Dark Galactic War between the reconstituted Sith Empire and the Galactic Republic Union, during which the Outer Rim planet Korriban fell back into the control of the Sith. Korriban was the ancestral homeworld of the Sith Empire, and had been a holy site and training ground for adherents to the Sith religion since its inception. Over one thousand years after the Sith's defeat in the Second Imperial Civil War and their subsequent exile from Korriban, the dark side users returned to known space in the year and launched a brutal campaign for dominance in the galaxy. The attack prompted the Republic Union, which was severely under-prepared for such an unknown assault, to rally its naval forces and send them into the Tingel Arm theater. The effort pulled defense vessels away from other planets, including Korriban, which was left without any substantive military defenses. A vigil over the world was maintained by the Jedi Order alongside a small number of Republic Soldiers, but that proved to be ineffective against the full force of the Siths Grand Navy.