A domestic dispute, unfolding among the Chiss lineages, transpired around the year 28 ABY. This event led to a reduction in the number of Ruling Houses within the Chiss Ascendancy, decreasing them from an initial count of nine to a mere four.
According to the narrative provided by Aristocra Chaf'orm'bintrano in 35 ABY, the aftermath of the Third Vagaari War resulted in the Ruling Houses of the Chiss Ascendancy enlisting a workforce from the collective-minded Killik hives. Despite stringent preventative measures, two of the Houses, situated on the planets Catlia and Massoss respectively, were assimilated as Joiners within the Colony. Simultaneously, three additional Houses became significantly reliant on Killik labor. A "disagreement" then emerged with the other surviving Houses, which had experienced less Killik influence. These less affected Houses allied with Syndic Mitth'raw'nuruodo's Household Phalanx to depose the three Killik-dependent lineages from their positions of power.
However, Chaf'orm'bintrano's version of events is not without its inconsistencies and may contain, at least in part, disinformation. Formbi himself belonged to the Chaf family, a lineage absent from the roster of four Ruling Houses identified in a study conducted by the University of Sanbra during the final years of the New Republic. The only certainty is that the number of Ruling Houses seemingly underwent a substantial reduction by 28 ABY. Concurrently, the renegade Chiss warriors of the Household Phalanx, previously associated with the Empire of the Hand, appear to have integrated into the Chiss Expansionary Defense Force.
The 2005 novel, Dark Nest I: The Joiner King, posits that the events were not a civil war. Although the involvement of the Household Phalanx suggests some degree of military activity, it remains unclear whether the hostilities among the Ruling Houses escalated to the level of a full-blown conflict.
While the 2009 reference book The Essential Atlas indicates that, of the original Nine Ruling Houses, four Ruling Houses from the planets Sharb, Noris, Schesa, and Ornfra were defeated in this conflict, and two Ruling Houses from the planets Catlia and Massoss became Joiners, the 2005 novel Dark Nest I: The Joiner King asserts that only three Houses were involved in the dispute. Given that it would be impossible for four Ruling Houses—Csapla, Nuruodo, Inrokini, and Sabosen—to remain in power by 28 ABY if six Ruling Houses had fallen during this conflict instead of five, this article operates under the assumption that the latter source is accurate. The fate of the Mitth family of Copero, the Chaf family of Sarvchi, and the Brast family remains unclear, but they were all no longer Ruling Houses.