Following his unsuccessful coup d'etat against Emperor Palpatine, Grand Admiral Zaarin and his fleet of Imperial traitors retreated into the far reaches of Imperial space, igniting a brutal campaign of destruction to deny the Galactic Empire of the military resources to resist his attempts to usurp power from the Emperor. Having had near unlimited access to the Empire's most power weapons and starfighters prior to his treachery, Zaarin held a huge technological edge over his loyalist adversaries in their attempts to put down his insurrection, as well as a formidable star fleet capable of maintaining the offensive against the Empire. Having laid waste to many Imperial industrial centers across the galaxy but at a staggering cost to his own forces, Zaarin eventually retreated into the Unknown Regions where he would continue to wage his campaign against the Emperor's forces.
Meanwhile, Vice Admiral Thrawn had been promoted to Grand Admiral by Emperor Palpatine and was personally tasked with the destruction of Zaarin and his traitorous forces. Recognizing the urgent need to match Zaarin's technological superiority in space combat, Thrawn secretly commissioned the production of a new class of starfighter known as the Missile Boat, specifically designed with the ability to match the performance Zaarin's vast fleet of TIE/D Defenders that formed the mainstay of his fleet of starfighters. Tan Maarek Stele, one of the Empire's greatest pilots was among those chosen to fly the Missile Boat in combat, and was assigned to Thrawn's command in the campaign to defeat Zaarin.
During the campaign in the Unknown Regions, Captain Kuuztin of the Imperial-class Star Destroyer Courageous became especially eager to be the one to catch Zaarin with his guard down so that he could crush the traitor's forces through one swift blow that he hoped would grant him huge favor among the inner ranks of the Imperial Navy. After a raid on one of Zaarin's convoys, Kuuztin extracted valuable intelligence from several captured traitors that pointed to a major supply base in the Gwar system that served as a "marshaling area" for a large portion of Zaarin's fleet. He also had reason to believe that Zaarin was plotting a major ambush upon Imperial forces loyal to the Emperor, with the forces stationed at this facility. Despite the obvious risks of such an attack, Captain Kuuztin elected to launch an immediate surprise assault upon the base and to wipe out the traitor forces there, without notifying Grand Admiral Thrawn of his intent. Some officers speculated that Kuuztin's actions were motivated out of an eagerness for promotion and possibly even hoped to replace Thrawn if such an attack succeeded. Nevertheless, the Imperial forces under Kuuztin's command immediately made preparations to engage Zaarin's fleet at Gwar, with Maarek Stele leading the assault.
Captain Kuuztin opted for a forward assault upon Zaarin's supply base with the Courageous spearheading the attack. It was determined that among the vessels present at the base were the Interdictor Bomb and its trio of Nebulon-B2 frigates from Kuma group. These, along with the supply platform were to be the main targets of the attack. It was also expected that the base would be defended by a minefield and a huge fighter screen led by Zaarin's TIE/D Defenders, which would easily wipe out the Courageous' complement of TIE/LN starfighters and TIE bomber. Therefore, Stele would fly an advanced Missile Boat with the intent of wiping out any and all TIE Defenders in the area should they be deployed during the battle. Until then, Stele was to clear a path for all fighter wings to attack the station and its flotilla of starships, along with any freighter craft or supply caches present in the area.
The Courageous launched its assault on the supply base with several wings of TIE Fighters and Bombers, who proceeded to immediately engage the station and its defenders. Stele led the assault in his Missile Boat, designated Mu 1, and laid waste to the platform's minefield before serious losses on the loyalist fighters could be inflicted. The loyalists then proceeded with their assault on the Bomb, with Stele knocking out its warhead launcher ahead of his allies. Frigates Kuma 1 and Kuma 3 were already maintaining patrol around the base's perimeter, and fired upon the loyalist forces that approached them.
The loyalist Imperial forces pressed their attack and laid waste to the various freighter and container craft present in the area, depriving Zaarin of many critical war supplies. Also caught in the crossfire was a shuttle ferrying officers loyal to Zaarin, which was quickly dispatched while attempting to flee the platform. The Fighters and Bombers held off Zaarin's waves of shielded TIE Interceptors while Stele pressed his attack on the Bomb and its accompanying frigates, eventually destroying all starships present with a barrage of heavy rockets.
With the station's defenses faltering and the loyalists pressing their attack on the platform itself, Zaarin sent his wings of TIE Defenders to ambush the Courageous. At this time, enemy frigate Kuma 2 also appeared in close proximity to the Courageous in a daring counterattack, forcing Stele to break off his assault to defend his command vessel. In the dogfight that followed, Stele was able to eliminate many of Zaarin's prized TIE Defenders, and eventually destroyed Kuma 2 as it pressed its futile attack, allowing the surviving loyalists to eventually destroy the supply platform and mop up the remaining enemy fighters and freighters in the immediate vicinity.
As the battle raged, the civilian bulk freighter Tallinn jumped into the region ferrying a full load of spare parts for Zaarin's forces at the base. It and its cargo also fell victim to the attacking loyalists, having gotten itself caught in the crossfire.
However, just as the Imperial forces under Kuuztin's command declared victory the Star Destroyers Imperator and Thunderer, which were loyal to Admiral Zaarin hypered into the region flanking both sides of the Courageous, with several fresh wings of TIE Defenders providing support as they assaulted the loyalist command vessel.
The resulting melee resulting in heavy casualties to the assaulting loyalist forces, and the Courageous itself eventually succumbed to a heavy bomb attack that claimed all hands aboard, including Captain Kuuztin. Stele however routed Zaarin's TIE Defenders and escaped the battle with his life, keeping his valuable starfighter out of enemy hands.
The Battle of Gwar was considered a major, if costly Imperial victory that resulted in the destruction of many of Zaarin's prized warships and advanced starfighter craft. The further loss of a massive amount of war materials and weaponry, as well as of one of Zaarin's primary staging grounds would come to considerably wear upon his offensive capabilities against the Empire.
However, the loss of the Courageous and its decorated captain proved demoralizing to the loyalists who had been unprepared for such a trap by Zaarin's superior force of Star Destroyers, and great strides would be taken to ensure that such a costly "victory" would not be repeated.