The Chiss Ascendancy was the regional galactic government of the Chiss species that controlled a portion of the Unknown Regions. They were very secretive and had little contact with the rest of the galaxy. It was governed by members of prominent ruling families known as the Aristocra.
- "What exactly do you wish from my Empire?"
"A state of mutual gain, I offer my knowledge and skill to you now in exchange for your consideration to my people in the future."
- ―Emperor Sheev Palpatine and Mitth'raw'nuruodo
Thrawn chose a planet in Wild Space to begin his fake exile and set up a hut designed to look as though he had been living in it for years. After a several attempts over many standard months, he was able to finally gain the attention of the Empire. The Venator-class Star Destroyer Strikefast led by Captain Voss Parck arrived at the planet searching for smugglers and discovered and examined Thrawn's encampment, finding Sy Bisti markings on the crates in the camp, warranting for the activation of the Imperial Unknown Alien protocols. Thrawn however managed to crash a V-Wing starfighter surveying the planet and attacked several Imperial troops, tricking them, and thus allowing him to get aboard the Strikefast. When Parck sent troopers to intercept him, Thrawn allowed himself to be captured without resistance.
Thrawn was then brought before Galactic Emperor Palpatine on Coruscant in order to be questioned who once in the Imperial Palace told the Emperor of threats lurking within the Unknown Regions, and how they might one day find the Empire and offered his military skills. Palpatine then deduced that his intentions were to help protect his people. Thrawn then assured the Emperor that his allegiance would be to the Empire and revealed that he had known Anakin Skywalker during the Clone Wars. It was then only that he proved who he was to the Emperor and was then able to forge an partnership between the Ascendancy and Empire, thus completing what was required by the Aristocra. Thrawn would become the Chiss ambassador to the Empire with the Emperor accepting Thrawn's offer to serve as his advisor on matters relating to the Unknown Regions and permanently assign Ensign Eli Vanto as his translator and aide. They would also both be assigned to the Royal Imperial Academy where Thrawn would soon graduate and rise up the ranks to become a Grand Admiral of the Imperial Navy and be given the command of the Imperial Navy Seventh Fleet and the Emperor reassured him that he had no ill intentions towards the Chiss Ascendancy and claimed that the Death Star would bring an end to all opposition. Despite his aid in helping the Empire to map the Unknown Region's hyperspace routes, Thrawn did however decide to withhold the location of Chiss worlds and bases. He would later be assigned to wipe out a growing rebellion against the Empire, while sending Vanto to the Ascendancy as an emissary where he met Admiral Ar'alani of the Chiss Defense Fleet and told her that Mitth'raw'nuruodo had sent him because he believed that he could be a great help to the Chiss. Ar'alani then openly welcomed Eli to the Chiss Ascendancy.
The Chiss Ascendancy was governed by members of the prominent ruling families called the Aristocra as part of a governmental hierarchy. They had the power to bless decisions across the Ascendancy.