The Mission to Honoghr occurred during the Thrawn campaign. As part of this mission, Leia Organa Solo successfully persuaded the Noghri to align themselves with the New Republic.
During the events of the Thrawn campaign, Grand Admiral Thrawn instructed the Noghri to abduct the expectant Leia Organa Solo. All Noghri met their fate except Khabarakh of Clan Kihm'bar. Eventually, the Noghri came to recognize Leia as the Mal'ary'ush, which translates to daughter of the savior: Darth Vader.
Understanding that her safety, as well as that of her children, was compromised while the Noghri remained in service to the Empire, and recognizing the potential advantage of her Mal'ary'ush status, Leia Organa journeyed to Honoghr alongside Khabarakh. Her goal was to convince the Noghri to sever their ties with the Empire.
Her initial encounter was with the maitrakh of Clan Kihm'bar, who agreed to offer her support. The maitrakh provided her with refuge when Grand Admiral Thrawn arrived on Honoghr in search of Khabarakh, harboring suspicions about his allegiance to the Empire.
Following Thrawn's departure, the maitrakh consented to convene the council of dynasts in Nystao to facilitate a discussion with Leia. She leveraged her lineage as the daughter of Darth Vader to successfully persuade some Noghri that the Empire had been deceptive, effectively keeping them in a state of servitude for an extended period. However, it was the demonstration that the Imperial Decon droids and the kholm-grass planted by the Empire were the cause of Honoghr's deterioration that led all the dynasts to realize the extent of the Empire's betrayal.
Consequently, the Noghri rebelled against the Empire and threw their support behind the New Republic. Grand Admiral Thrawn met his end when his Noghri protector, Rukh, betrayed him, fatally stabbing him during the Battle of Bilbringi.
Leia and her family became highly esteemed figures within Noghri society. The New Republic assisted in relocating the Noghri to other planets, including Wayland, to allow Honoghr the necessary time for recovery.