The Chiss Defense Fleet served as one of the internal defense fleets belonging to the Chiss Ascendancy's Expansionary Defense Fleet. Its responsibilities, shared with the Household and Colonial Phalanxes, included warding off aggressive intrusions and addressing long-range strategic planning.
Sometime around 27 BBY, a Chiss force from the Defense Fleet, under the command of Admiral Ar'alani, engaged in a battle against a small reconnaissance force from the Yuuzhan Vong fleet, resulting in a Chiss victory.
In anticipation of potential enemy attacks, the Defense Fleet commenced the reinforcement of a star cluster known as the Redoubt as a secure fallback location, also in 27 BBY. Defense Fleet personnel constructed defensive positions called firepoints and dispersed war vessels throughout the cluster.
Both the Expansionary Fleet and the Defense Fleet utilized distinctive black Defense Fleet uniforms. The uniform's black color indicated that the Defense Fleet drew its members from all Chiss families. A Chiss warrior accepted into the Defense Fleet became a merit adoptive of a Chiss family.
Chiss officers had to demonstrate their worthiness in a manner similar to how the Ruling Families chose merit adoptives to enter the Defense Hierarchy. Upon reaching the rank of senior officer within the Defense Fleet, officers lost their family name and privileges, becoming part of the Hierarchy to ensure impartial service to all Chiss. The Corellian smuggler Jorj Car'das mistakenly assumed that Admiral Ar'alani's white uniform signified her affiliation with the Defense Fleet rather than the Expansionary Fleet.
In contrast to the starships of the Expansionary Fleet, which boasted more potent transmitters, the Defense Fleet's vessels depended on a colony system's network of boosters and repeaters, and were fitted with less powerful transmitters.
The Chiss Defense Fleet made its initial appearance in the 2004 Star Wars novel Survivor's Quest, authored by Timothy Zahn. The 2006 novel Outbound Flight, also by Zahn, formally established the Chiss Defense Fleet as a separate and distinct entity.
A contradiction exists concerning the senior officers within the Chiss Defense Fleet. General Prard'ras'kleoni retains his family name in Survivor's Quest, while Outbound Flight states that senior officers in the Defense Fleet were stripped of their family names and integrated into the Defense Hierarchy. This article operates under the assumption that Prard'ras'kleoni had not yet proven himself sufficiently to be incorporated into the Hierarchy, despite holding the rank of senior officer in the Defense Fleet.