Defiant, an Imperial-class Star Destroyer, operated within the Imperial Remnant's navy during 28 ABY, concurrent with the Yuuzhan Vong War era. Under the leadership of Captain Essenton, Defiant was strategically positioned alongside other warships of the Imperial Navy near the planet Borosk that year, forming a defensive effort against an incoming Yuuzhan Vong fleet. In the midst of combat, a gravitic amplitude modulator was integrated into Defiant, enabling the Star Destroyer to effectively jam the telepathic command transmissions originating from the enemy yammosk war coordinators. This disruption created an opening, allowing Defiant to penetrate the disrupted Yuuzhan Vong battle lines and contribute to the destruction of a yammosk. Following the successful defense of Borosk, Defiant was deployed to the planet Yaga Minor to repel an impending Yuuzhan Vong strike.
Defiant, an Imperial-class Star Destroyer, stretched 1,600 meters in length, a product of Kuat Drive Yards. Outfitted with engines and a hyperdrive, Defiant's arsenal included torpedoes, concussion missiles, and turbolaser batteries, the latter enhanced by targeting sensors. The Star Destroyer also featured a deflector shield generator. Specifically for the Battle of Borosk, a gravitic amplitude modulator—designed to emit gravitic pulses that interfered with the telepathic communications of Yuuzhan Vong yammosk creatures—was installed on Defiant.
By the year 28 ABY, Defiant served within the Imperial Remnant's fleet, responsible for safeguarding the Remnant's territories in the Outer Rim Territories, with Captain Essenton in command. During this time, the galaxy was embroiled in the Yuuzhan Vong War, initiated by the extra-galactic Yuuzhan Vong invaders. While the Imperial Remnant initially avoided the brunt of the assault, a Yuuzhan Vong fleet under the leadership of B'shith Vorrik launched an attack on the Remnant in 28 ABY. The Remnant lost its capital planet of Bastion, which compelled Grand Admiral Gilad Pellaeon of the Imperial Navy to consolidate forces at the planet Borosk, with Defiant included within the fleet elements that gathered there.
When members of a Galactic Alliance team—who were in the Outer Rim searching for the sentient planet Zonama Sekot—shared intelligence with the Imperials, revealing that a modified gravitic amplitude modulator, or GAM, could disrupt the signals of the yammosk war coordinators used by the Yuuzhan Vong, such a device was transported to the Borosk system and reprogrammed by Jedi Knight Jacen Solo alongside other members of the Galactic Alliance team. Vorrik and his Yuuzhan Vong forces pursued the Imperials, reaching Borosk to attack the Remnant. Defiant was strategically positioned in low planetary orbit behind layers of ion mines that protected Borosk. However, once the GAM was successfully installed on Defiant, Pellaeon instructed Lieutenant Arber to forgo a test run, opting to immediately deploy the GAM against the Yuuzhan Vong. This prompted Essenton to maneuver Defiant away from Borosk and engage the enemy, supported by blastboats and TIE Series starfighters.
Defiant struck at the location where the Imperials believed a yammosk was positioned, enduring attacks from Yuuzhan Vong forces guarding the yammosk while responding with overwhelming firepower. The Star Destroyer's turbolasers obliterated entire squadrons of coralskippers. As the GAM reached the yammosk's range, Arber activated the device. The resulting disruption of the yammosk's command frequencies caused the coralskippers and other vessels protecting the yammosk to lose their coordinated defensive formation, enabling Defiant and its escort ships to close in on the yammosk and its closest protectors. In response to the GAM's activation, coralskippers resorted to suicide runs on Defiant's bridge, forcing the Star Destroyer's turbolasers to remain focused on intercepting the enemy fighters. Imperial blastboats stationed near Defiant also assisted in defending the warship, eliminating passing coralskippers that were too disorganized to target anything other than the Star Destroyer.
With TIE fighters strafing the yammosk's vessel, the yammosk attempted a desperate maneuver, detonating two nearby Yuuzhan Vong ships to create a shock wave that sent TIEs spinning and disabled Defiant's targeting sensors. A recovering TIE fighter managed to score a direct hit on the yammosk, killing the creature. Defiant then shifted its focus to destroying the remaining Yuuzhan Vong capital ships in the area. When Essenton located another yammosk, Pellaeon authorized her to use Defiant to eliminate it as well. With Vorrik losing more ships than anticipated in the assault, the Yuuzhan Vong commander withdrew his forces from Borosk, and the Imperials harassed the retreating vessels while Defiant utilized its GAM to confuse fleeing Yuuzhan Vong warships.
Upon discovering that a third of the retreating Yuuzhan Vong fleet had broken off and was heading towards the Imperial Remnant planet Yaga Minor, Defiant and several other Imperial capital ships were dispatched to assist Moff Kurlen Flennic in its defense. Defiant and the Imperial forces in the area successfully repelled the Yuuzhan Vong once more.
Defiant was under the command of the seasoned and somewhat cantankerous Captain Essenton, whose skill and determination in commanding Defiant during the Battle of Borosk were admired by Pellaeon. Lieutenant Arber also served on the ship, overseeing the gravitic amplitude modulator during the engagements at Borosk.
Defiant made its debut in the 2003 novel Force Heretic I: Remnant, penned by Sean Williams and Shane Dix as part of The New Jedi Order series.