In the year 18 BBY, a crisis unfolded within the Chiss Ascendancy. At the astronomical object Csaus, located in the Chiss Unknown Regions, the battle at Csaus took place. It involved armed freighters belonging to the Ascendancy's Tahmie and Droc families. These freighters exchanged spectrum laser fire until Admiral Ers'ikaro of the Chiss Defense Force intervened with his Firewolf man-of-war, the Bellicose. His intervention was to halt the battle and prevent further escalation of the ongoing crisis.
Clarr'ivl'exow, the Patriarch of the Clarr family, later inquired of Captain Clarr'os'culry of the Clarr family—who considered the conflict at Csaus to be minor—regarding her awareness of the engagement. The officer confirmed that she was aware. Soon after, the Tahmie and Droc resumed their conflict on the planet Jamiron.
The 2021 novel Thrawn Ascendancy: Lesser Evil, which is the concluding book in Timothy Zahn's Thrawn Ascendancy Trilogy, makes reference to the battle at Csaus.