The Expedition to Korriban was an exploratory mission to the Sith world of Korriban that was mounted by a force of Republic warships and soldiers. Taking place approximately one year after the end of the Jedi Civil War, the expedition's purpose was to assess the situation on the Sith world and deal with any rogue factions of Darth Revan's Sith Empire that still remained.
By the time they Republic force arrived at the barren world, however, the last vestiges of the Sith remnants there had long since destroyed themselves in internecine fighting. When Republic troops arrived on the surface, they found a smashed landscape that was littered with the corpses of dead Sith, with broken monuments, sealed-off tombs, and half-buried archaeological digs filling the Valley of the Dark Lords. The Sith Academy there was likewise in a state of abandonment, with ruined architecture everywhere; the settlement of Dreshdae was also abandoned. With nothing left to deal with, the Republic forces soon returned home.
In the wake of the Republic's exploratory mission, a number of treasure hunters descended upon the planet, hoping to find some worthwhile artifacts to salvage. By the time Meetra Surik arrived in 3951 BBY, barely any traces were left of the Sith presence that had been there during the civil war. Within the Academy, however, she found not only traces of still-active terminals and evidence of activity—both from treasure hunters and would-be Sith—but also Darth Sion, who had been hunting her.
The expedition is alluded to several times in Star Wars: Knights of the Old Republic II: The Sith Lords, particularly during conversations with Kreia, when she offers up details of the Jedi Civil War and the conflicts that followed. When the player does visit Korriban, they are unable to enter any of the tombs, and the passageway to Dreshdae is sealed; however, since landing at the spaceport there is not possible, it can be assumed that the city was abandoned by both the Sith and Czerka Corporation.
The expedition is alluded to several times in Star Wars: Knights of the Old Republic II: The Sith Lords, particularly during conversations with Kreia, when she offers up details of the Jedi Civil War and the conflicts that followed. When the player does visit Korriban, they are unable to enter any of the tombs, and the passageway to Dreshdae is sealed; however, since landing at the spaceport there is not possible, it can be assumed that the city was abandoned by both the Sith and Czerka Corporation.