The Chiss Expansionary Defense Fleet, which is also known by the names Chiss Expansionary Fleet, Chiss Defense Fleet, and Ascendancy Defense Fleet, served as the external defense fleet for the Chiss Ascendancy's military. Its purpose was to safeguard Chiss interests beyond the Ascendancy's borders and to probe any potential dangers originating outside of Chiss space. The Fleet was constrained by a series of laws prohibiting pre-emptive strikes.
This fleet conducted its operations within the Unknown Regions of the galaxy, and its ranks included figures such as Admiral Ar'alani, a female Chiss officer, and Senior Captain Mitth'raw'nuruodo before his enlistment in the Galactic Empire. Eli Vanto, a human commander within the Imperial Military and a close acquaintance of Thrawn, later joined the fleet as an Imperial liaison dispatched by Thrawn to the Chiss Ascendancy. The fleet also utilized distinctive military uniforms.
Leading up to the Nikardun conquests, the Chiss Defense Force had repeatedly urged the governing Chiss Syndicure to broaden its capabilities and authority. Shortly before Kivu'raw'nuru, a young Chiss from a modest family, was recruited to become a member of the esteemed Mitth family, the Syndicure ultimately conceded. They established the Chiss Expansionary Defense Fleet, tasking it with the mission of "overseeing Chiss interests in the regions of the Chaos that extended beyond the Ascendancy's boundaries, identifying external entities, and evaluating the threats they posed." During that time, the Aristocra allocated resources for the construction of numerous new ships, bases, and logistical facilities, creating a demand for skilled officers and warriors within the newly formed Expansionary Fleet.
By the time the Clone Wars erupted, the Chiss Expansionary Defense Fleet served as the active external arm of the Chiss Defense Force. During the conflict, Senior Captain Mitth'raw'nuruodo, an officer within the Chiss Defense Fleet, was stationed near the Outer Rim world of Batuu on a specific assignment. It was here that he crossed paths with Jedi General Anakin Skywalker from the Galactic Republic. Thrawn aided Skywalker in destroying a Separatist droid factory located on the isolated planet of Mokivj. Subsequently, he returned to Chiss space with a deflector shield generator, which he referred to as a "Republic energy shield," noting its superior capabilities compared to the electrostatic barriers used by the inhabitants of the Unknown Regions at that time. Thrawn then deployed the "Republic energy shield" aboard his vessel, the Springhawk, to assist in the defeat of Yiv the Benevolent, a General from the Nikardun.
Following the defeat of Yiv, the Ascendancy dispatched the Fleet on the Nikardun campaigns with the objective of eliminating the remaining elements of the Nikardun Destiny. The Syndicure considered the Nikardun forces a significant enough threat to justify relaxing the non-aggression protocols and authorizing the campaigns.
Throughout the Galactic Civil War, the Chiss Expansionary Defense Fleet continued its operations. Following the Batonn insurgency, Thrawn was elevated to the rank of Imperial Grand Admiral. He sent his trusted friend and protégé, Commander Eli Vanto, to meet with Admiral Ar'alani of the Chiss Expansionary Defense Fleet and join the Chiss Ascendancy. During the Imperial–Grysk conflict, Chiss Defense Fleet units kept watch on the battle against Grysk forces.
The Chiss Expansionary Defense Fleet functioned as the external naval component of the Chiss Ascendancy's military forces, collectively known as the Ascendancy military. The Chiss Ascendancy was governed by the Syndicure and the Aristocra, yet officially, the politics of the Chiss family were not supposed to influence the Defense Fleet's decisions. However, in reality, there were indeed "unofficial" instances where they played a role. It was generally understood that the Syndicure's decisions, while not direct orders, carried considerable weight.
The Chiss Expansionary Defense Fleet employed a range of military ranks, including Admiral and Commander. A key aspect of the Chiss Expansionary Defense Fleet's mandate was the defense of Chiss colonies, along with monitoring conflicts between other factions and governments. The Expansionary Defense Fleet was also prohibited from intervening in events occurring within Chiss territory, a responsibility that fell to the Chiss Defense Force.
Officers serving in the Chiss Expansionary Defense Fleet were equipped with a specialized type of uniform designed to absorb energy, thereby providing protection against blaster fire. Chiss uniforms were typically black in [color](/article/color], with the exception of ozyly-esehembo's uniforms, which were white, and prominently displayed the emblem of the Chiss Ascendancy on the upper arm. Rank was indicated by silver insignia pins affixed to the collar of the uniform. These rank bars were absent on the uniforms worn by cadets. Officers and cadets affiliated with one of the Nine Ruling Families wore a shoulder patch bearing that family's insignia.
There were occasional deviations from the standard Chiss uniform, such as Admiral Ar'alani's preference for a pure white uniform, which contrasted sharply with the black uniforms worn by her crew.
The Chiss Defense Fleet operated a variety of starships, including Chiss heavy cruisers such as the Steadfast. The Chiss vessel Whirlwind was also a part of the fleet. Chiss shuttles, sometimes referred to as Chiss courier ships, were also deployed. Chiss defense platforms were also utilized by the Chiss Defense Fleet. Another type of warship used by the Chiss was the Nightdragon man-of-war. Other ships such as missile boats, patrol cruisers, patrol ships, freighters, heavy cruisers, and destroyers were used.
The Chiss Expansionary Defense Fleet made its initial appearance in Star Wars canon within the 2017 novel titled Thrawn, authored by Timothy Zahn. The Defense Fleet's origins can be traced back to the 1998 Star Wars Legends novel Vision of the Future, and it subsequently appeared in the 2004 novel Survivor's Quest, both penned by Zahn.