Around the year 36 BBY, a brief battle occurred in the Kinoss system of the Chiss Ascendancy. This fight was between the Chiss Expansionary Defense Fleet and pirates belonging to the Lioaoin Regime. Before this skirmish, Junior Commander Mitth'raw'nuru, known as "Thrawn," who was a member of the Expansionary Defense Fleet, was convinced that he could demonstrate the Regime's support of piracy targeting the Chiss and other groups in that region. Consequently, he embarked on a mission to the Lioaoin heartworld while pretending to be a merchant. He openly announced his discovery of pirates and intentionally provoked Lioaoin security ships into attacking his own ship.
Both Thrawn and the Lioaoin pirates relied on Pathfinder navigators for navigation. These navigators possessed a unique capability: they could track each other through hyperspace by using the Force. Thrawn exploited this ability by enticing the Lioaoin corsairs to chase his freighter through hyperspace, leading them to the Kinoss system. There, Mid Captain Irizi'ar'alani commanded the Chiss patrol cruiser called Parala and was waiting in ambush. The corsairs walked right into Thrawn's trap and were promptly destroyed by the Parala upon their arrival. As a result of this skirmish, the involved Chiss officers received promotions.
Following Mitth'raw'nuru "Thrawn"'s promotion to the military rank of Junior Commander within the Chiss Expansionary Defense Fleet, pirates began attacking merchant ships belonging to the Chiss Ascendancy for several months. The Ascendancy's preemptive-strike laws prevented military action against potential culprits until their guilt could be established, even if members of the Chiss Syndicure and the Ascendancy military had their suspicions about a particular group.
While on a diplomatic mission to the Scofti homeworld of Bardram Scoft, Junior Commander Thrawn observed ships of the Lioaoin that looked like the pirates who were plundering freighters on the Ascendancy's borders. He became convinced that he could prove that the Lioaoin Regime was supporting these pirates. Thrawn had also discovered that the Pathfinders from the Navigators' Guild had the capability to track and pursue each other through hyperspace.
Around 36 BBY, soon after a pirate attack that Thrawn suspected involved the Lioaoi and Pathfinder navigators, he asked the Expansionary Fleet's Supreme General Ba'kif for permission to undertake a mission to the Lioaoin heartworld. Thrawn's plan was to either confirm his theory or take no action, adhering to the Ascendancy's preemptive-strike laws. He wanted to carry out his mission quickly, before the Regime's hired Pathfinders could return to Navigators' Guild stations. If Thrawn's suspicions were correct, he would entice Lioaoin Regime forces or their pirate allies to attack the Chiss, proving his theory and effectively starting the Lioaoin pirate campaign. Ba'kif granted him permission for the mission, providing two freighters disguised as Chiss merchants seeking trade with the Lioaoin heartworld, as well as a Chiss patrol cruiser that would lie in wait at a pre-arranged location.
Thrawn enlisted the Pathfinder navigator Qilori to guide his freighter to the Lioaoin heartworld, posing as a Chiss merchant. Another Chiss freighter, navigated by a different Pathfinder, accompanied Thrawn on this mission. Thrawn correctly believed that the Lioaoin pirates employed Pathfinders to navigate their ships. His strategy was to use the Pathfinders' ability to follow each other through hyperspace to lure forces from the Lioaoin Regime or their pirate associates into a trap, which would definitively prove that the attacking pirates had the Regime's approval.
Qilori could sense some of his Pathfinder colleagues aboard Lioaoin pirate ships through the Force and cautioned Thrawn about the dangers of searching for pirates. Qilori emphasized that if the Regime suspected that he and Thrawn were hunting pirates, they would be in danger. Thrawn interrupted Qilori's warning, realizing that the Lioaoin Regime might only suspect that he was hunting pirates, and decided to eliminate any doubt. Therefore, he announced in Minnisiat, a trade language understood by the Lioaoi, that he had discovered pirates, and instructed the other Chiss freighter to "report back." Thrawn then retreated to the Kinoss system via hyperspace, pursued by the pirates he intended to trap, whose Pathfinders followed him by sensing Qilori.
Shortly after Thrawn and Qilori arrived in the Kinoss system, four Lioaoin corsair starships emerged from hyperspace behind them, ready to attack. However, Mid Captain Irizi'ar'alani, known as "Ziara," who commanded the Chiss patrol cruiser Parala, was waiting in ambush above the planet Kinoss and swiftly destroyed all four Lioaoin pirate ships. To Qilori's dismay, this included the Pathfinders who were aboard the corsairs.
Following the Kinoss operation, Thrawn received a double promotion, advancing from Junior Commander to Senior Commander, skipping the rank of Mid Commander altogether. Mid Captain Ziara was promoted to Senior Captain. This skirmish marked the beginning of the Chiss' campaigns against the Lioaoin pirates.
Just before his promotion, Thrawn requested permission from Ba'kif to launch an attack on the Lioaoin heartworld. Ba'kif responded angrily, stating that they absolutely could not attack the heartworld without undeniable proof of the Lioaoin Regime's guilt, as dictated by the Ascendancy's non-aggression protocols. Ba'kif believed that Thrawn had eliminated the Lioaoins as a threat to the Ascendancy. However, Thrawn was not content to leave them as a threat to others in the Unknown Regions. Thrawn's desire to protect other nations from the pirates eventually led to the Stivic incident, where he secretly informed Garwian defenders at their colony world of Stivic about how to defeat attacking Lioaoin pirate ships.
Several years later, in 19 BBY, Thrawn returned to Guild Concourse 447 to hire Qilori for his planned raid on Rapacc. Qilori was surprised that Thrawn, who had been a Junior Commander during the Kinoss events, had risen to the rank of Senior Captain so quickly. However, the navigator then realized that it should not have been a surprise, considering Thrawn's performance during the skirmish in the Kinoss system.
The skirmish that took place in the Kinoss system was depicted in flashbacks in the 2020 novel Thrawn Ascendancy: Chaos Rising by Timothy Zahn, which was the first book in Star Wars: The Ascendancy Trilogy.