In early Lioaoin history, they conquered one of the Garwian Unity's outer worlds.
The Lioaoin Regime was established in the Unknown Regions. This area was extremely hard to navigate using hyperspace and forced the Regime to use navigators from the Navigators' Guild, especially the Void Guide group. The Regime often clashed with other small nations that rose up in the Unknown Regions and was frequently at odds with the Chiss Ascendancy.
Eventually, their economy began to decline and the Regime began piracy to keep it alive. This lead them to raid the nearby Chiss systems of Pesfavri, Schesa, and Massoss for months. This brought them into conflict with Junior Commander Thrawn. Thrawn eventually figured out that the pirate ships were in fact Lioaoin and state-sanctioned, despite the Regime officially denying it. Thrawn then hired Pathfinder Qilori of Uandualon and traveled to the Lioaoin heartworld. Junior Commander sent out a transmission on an open channel in a trade language known by the Lioaoi, confirming that he had found the pirates and ordering a second Chiss ship to report back to the Ascendancy. As Thrawn made his own escape, three Lioaoin pirate corsairs launched a pursuit, attempting to trap Thrawn. Thrawn evaded, however, and traveled to the Chiss Kinoss system. Four Lioaoin corsairs, aided by their own Pathfinders, were able to follow Thrawn to Kinoss (Pathfinder navigators could follow each other trough hyperspace). Upon their arrival, however, a Chiss warship, under the command of Mid Captain Irizi'ar'alani (Ziara), appeared and quickly destroyed the ships. This skirmish marked the beginning of the Chiss Lioaoin pirate campaigns.
Later, Lioaoin pirates would attack the nearby Garwian Unity colony world of Stivic (specifically, an orbiting merchant-hub station). However, during the battle, the Chiss patrol cruiser Parala arrived. Garwian Security Officer Frangelic had sent out a distress signal, and Thrawn (having been promoted to Senior Commander), being in temporarily command of the Parala, responded. During the battle, the Garwians suddenly changed their tactics, forming a corkscrew maneuver that exposed the Lioaoin ventral sides to the Garwians (the Lioaoi overcorrected to the Garwian corkscrew maneuver). Due to this exposure, the Garwians were able to inflict severe damage to three of the four Lioaoin ships. The fourth Lioaoi pirate vessel escaped into hyperspace. Thrawn had secretly transmitted an encoded message to the Garwians, detailing the Lioaoi strategies and how to counter them.
Emboldened by the Lioaoin attack, the Garwian Unity launched a new campaign of conquest of Lioaoin space, aiming to reconquer their lost world and, potentially, even conquer on the Lioaoin worlds. Experiencing losses, the Lioaoi sent two diplomatic ships to Solitair to negotiate the Regime's surrender. However, upon arriving at Solitair, they would be immediately attacked by the Garwians. The Garwians were trying to get Thrawn, who was on Solitair, to reveal more tactical information about the Lioaoi to aid in their conquests. Eventually, this new conflict between the Lioaoi and the Garwians would conclude.
Several years later during the Clone Wars, a new threat emerged in the Unknown Regions. A powerful empire called the Nikardun Destiny, ruled by General Yiv the Benevolent, subjugated many of the smaller fractured nations. Secretly, they allied with the Lioaoin Regime to defeat the Ascendency. The Nikardun would train the Lioaoin military in new tactics and would give standing orders to attack any vessel with Thrawn in it. During this time, a Lioaoin ship had engaged in a net formation intended to capture the Chiss Vigilant Nightdragon man-of-war when it arrived at the Tower Dimension capital world of Urch. Upon escaping from this trap, the Vigilant made its way to the Lioaoin heartworld to demand answers from the Lioaoin Regime. To this, the Regime replied they had nothing to do with this. At this time, a Nikardun Battle Dreadnought was at the planet, but did not make any threatening moves. Thrawn, temporarily assigned to the Vigilant, directly communicated with the Lioaoin diplomats, revealing his name. Seven Lioaoin gunboats immediately reacted to the mention of his name, revealing their standing orders to the Chiss. However, their Nikardun commanders immediately told them to get back into their formation, wanting to appear as nonthreatening as possible.
The Vigilant would arrive at the Vak Combine homeworld of Primea to pick up Thrawn (who had been there on an undercover mission). Yiv had learned of Thrawn's presence at Primea and wanted to capture or kill him. His attempt at doing so failed, as Thrawn had anticipated his desires. Yiv, knowing that Thrawn was still on the planet, prepared for a Chiss extraction mission. He instructed four Lioaoi warships to arrive and attack any Chiss ships that arrive at Primea. When the Vigilant eventually arrives to extract Thrawn, these Lioaoin warships arrive and told the Vigilant to leave the system. After the Vigilant tries to explain their situation, the Lioaoi fire upon them. The Vigilant, recognizing its lack of firepower, immediately tries to leave the system. Thrawn, who had commandeered a Vak patrol craft, attacked and destroyed the weapons clusters of the outermost Lioaoin ship, which allowed the Vigilant time to secure Thrawn and escape the system.
In retaliation for the Lioaoin attack. The Chiss Ascendancy would send the Vigilant and Thrawn's Springhawk to the Lioaoin heartworld for an attack. Ar'alani attempted to contact the Lioaoi, but the Nikardun stationed on the heartworld forbid them from communicating with the Chiss. Upon seeing that there were only two Chiss ships, all the twelve present Lioaoin warships started to converge upon the Springhawk as a warning. The Lioaoi did not want to send all of their forces to meet the Chiss, however, because they feared more Chiss arrivals. Therefore, they only sent four warships in a diamond attack formation to meet the Chiss. The remaining eight ships settled themselves into a defensive high orbit. The Vigilant would tracker one of its shuttles towards the four attackers, but the Lioaoi were able to take control of the shuttle's movement with their own tractor beams. They set the shuttle on a course that would take it through the middle of their formation, but the Chiss anticipated this and fired upon the shuttle as it passed through. As the shuttle exploded, four breacher missiles launched towards and impacted the four Lioaoin ships. A second shuttle, which had followed the first, was exploded by the Chiss, revealing four more breacher missiles. This resulting chaos caused the four Lioaoin attackers to break from their formation, prompting two more Lioaoin warships to join them in battle. However, the Chiss were eventually able to achieve victory.