In the year 3996 BBY, following the defeat of Exar Kun at Yavin 4, the Galactic Republic reclaimed the Empress Teta system.
Following the final downfall of Sith Lord Exar Kun in the Yavin system, numerous Krath elements continued to operate freely within a galaxy struggling to recover from years of relentless and devastating conflict. While the termination or incapacitation of key figures in their hierarchy (Kun, Aleema Keto, Satal Keto, Ulic Qel-Droma) significantly impaired Krath operations, the Republic still had to deal with their firmly established territories located deep within the Empress Teta system.
Sometime after the Battle of Yavin 4, Republic military forces mounted a final offensive against the heavily defended Koros planets, ultimately gaining complete control of the system and dispersing the remaining Sith forces present.