Zaarin's fleet was a collection of former Imperial Navy warships, serving as the military arm of Grand Admiral Demetrius Zaarin's rogue government. Initially a part of the Galactic Empire's Imperial Military, this fleet sided with Zaarin following his defection and participated in his insurrection. They clashed with Imperial loyalists, especially the forces of Thrawn and Darth Vader. Zaarin's research into advanced TIE Series fighters gave his fleet a technological edge. However, this advantage did not prevent the fleet's eventual downfall.
The fleet was comprised of a variety of ships, from Imperial-class Star Destroyers to Delta-class DX-9 stormtrooper transports. TIE/D Defenders and TIE/ad starfighters served as the primary starfighters. A ground force of stormtroopers was also part of the fleet's composition. Following the Battle of Ottega, almost every unit in the fleet had a "Z-" prefix added to its name to identify its affiliation (for example, Z-Beta Squadron).