A mission was undertaken in 18 BBY by the Chiss sentient species' nation of the Chiss Ascendancy at the ede of Lesser Space, the term used by the Chiss for the territory beyond the Unknown Regions. The Ascendancy's Defense Hierarchy Council sent Senior Captain Mitth'raw'nuruodo "Thrawn"'s Chiss heavy cruiser Springhawk in an attempt to locate the Grysk warlike species' location following one of their fleet's destruction at the hands of Thrawn; however, during Thrawn's travels at the edge of Lesser Space, he did not locate any trace of the Grysks, and instead found a group of Neimoidian refugees who informed him of the end of the Clone Wars, a conflict between the Confederacy of Independent Systems and the Galactic Republic.
The Chiss was also informed of the rise of the Galactic Empire and was asked to bring the full might of the Ascendancy to the Empire's capital city of Coruscant in an attempt to destroy the Empire, kill Emperor Palpatine and bring back the Republic. Thrawn then went back to the Ascendancy's capital planet of Csilla. He later retold the mission to Admiral Ar'alani of the Chiss while explaining why he was being exiled.
The mission was first indirectly mentioned in the 2017 novel Thrawn, the first volume in the Star Wars: Thrawn novel series written by Timothy Zahn.
The mission was first indirectly mentioned in the 2017 novel Thrawn, the first volume in the Star Wars: Thrawn novel series written by Timothy Zahn.