The Third Fleet represented a fleet within the Imperial Navy, under the command of Grand Admiral Balanhai Savit. His command ship was the Star Destroyer known as the Firedrake.
The Third Fleet included a minimum of four Star Destroyers. The ISD Firedrake functioned as the flagship for the fleet and was under the joint command of Grand Admiral Balanhai Savit and Captain Boulag. Meanwhile, the Harbinger was led by Captain Gilad Pellaeon, the Misthunter by Captain Rasdel, and the Stormbird by Captain Lochry.
During the time of the Lothal campaign, the Firedrake saw use in the anti-piracy campaign in the Esaga sector. It also served as a location where Savit, fellow Grand Admiral Thrawn, Grand Moff Tarkin, Director Krennic, and a hologram of the Emperor convened. Following a skirmish with the Chimaera, the Third Fleet fell into disarray, resulting in Savit's removal from his position. Lochry and the Misthunter received orders to proceed to Aloxor with the purpose of neutralizing Savit's associates, while Boulag, aboard the Firedrake, transported Savit to Coruscant to face a board of inquiry conducted by Imperial High Command.
Emperor Palpatine instructed Pellaeon and the Harbinger to provide assistance to Thrawn on Lothal, which led to their involvement in the battle there. This engagement culminated in the Liberation of Lothal by rebel forces. During the conflict on Lothal, purrgil under the control of the Jedi Ezra Bridger successfully neutralized Pellaeon and the Harbinger.