After the empire collapsed following the defeat of Xer's son Xim the Despot at the Third Battle of Vontor, the Kingdom of Barseg was restored as one of the successor states of Xim's empire, and survived inclusion into the Galactic Republic in 23,900 BBY.
The Lianna provinces of Caldara and Berene led the last great independence war on Lianna against Barseg, which resulted in the annihilation of both provinces. The plight of Lianna was ignored by the Galactic Senate until the Senate itself took control of Lianna from Barseg in 300 BBY. While a member of the Galactic Republic, the fate of the kingdom after 300 BBY is currently unknown.