The Expedition to Korriban represented an exploratory undertaking. A contingent of Republic soldiers, supported by warships, journeyed to the Sith world of Korriban. This mission occurred roughly one year after the conclusion of the Jedi Civil War. Its primary objective was to evaluate the state of the Sith planet and neutralize any remaining rogue elements from Darth Revan's Sith Empire.
However, upon the Republic's arrival at the desolate planet, the last remnants of the Sith had already annihilated each other through internal conflicts. Upon landing, Republic forces discovered a devastated landscape strewn with the remains of Sith warriors. The Valley of the Dark Lords was filled with shattered monuments, inaccessible tombs, and partially excavated archaeological sites. The Sith Academy was similarly deserted and in ruins, and the settlement of Dreshdae was also abandoned. Finding no active threats, the Republic forces quickly concluded their mission and returned home.
Following the Republic's exploratory mission, numerous treasure seekers descended upon the planet, hoping to recover valuable artifacts. By the time Meetra Surik arrived in 3951 BBY, scarcely any evidence remained of the Sith presence that had existed during the civil war. However, within the Academy, she discovered not only traces of functioning terminals and signs of activity—both from treasure hunters and aspiring Sith—but also Darth Sion, who was hunting her.
Star Wars: Knights of the Old Republic II: The Sith Lords makes several references to this expedition, notably in conversations with Kreia, who provides details about the Jedi Civil War and the subsequent conflicts. When the player explores Korriban, they cannot access any of the tombs, and the passage to Dreshdae is blocked. Given the impossibility of landing at the spaceport, it can be inferred that both the Sith and the Czerka Corporation had abandoned the city.