- "Generals Farlander and Celchu have the enemy boxed in. Harbinger has dropped from hyperspace and is pressing forward at battle speed to rendezvous with Elegos A'Kla at rally point manka-flechette-dewback."
- ―Mon Mothma's commander, during the Battle of Corulag
Harbinger was a heavily armed Mon Calamari Star Cruiser that served as General Garm Bel Iblis' flagship in the later part of the Yuuzhan Vong War. Initially guarding the planet Tallaan from Yuuzhan Vong attack, Harbinger participated in the New Republic rout of Yuuzhan Vong forces in the Treskov system in 28 ABY. The Star Cruiser later aided the New Republic's successor state, the Galactic Alliance, in defending the planet Mon Calamari from a Yuuzhan Vong armada in 29 ABY. Harbinger and the Galactic Alliance forces met the armada at the edge of the Mon Calamari system, where the Star Cruiser made good use of its heavy weaponry. Following the battle, Bel Iblis and Harbinger joined Galactic Alliance fleet elements in liberating the planet Corulag from the Yuuzhan Vong.
- "Dovin basal singularities have been diverted to the forefront of the armada. Destroyers will be attacking the flanks in an attempt to induce the dovin basals to shift focus, so that Harbinger, Guardian, and Viscount can resume fire."
- ―Galactic Alliance control, during the Defense of Mon Calamari
In the year 28 ABY, during the Yuuzhan Vong War, in which the extra-galactic Yuuzhan Vong invaded the galaxy, Harbinger served as the flagship of fleet elements used by New Republic–allied General Garm Bel Iblis to guard the planet Tallaan against the invaders. Harbinger traveled alongside half of the fleet from Talaan as Bel Iblis answered Jedi Master Luke Skywalker's call to aid the New Republic in creating a trap for the Yuuzhan Vong in the Deep Core's Treskov system, near the moon Ebaq 9. Once the Yuuzhan Vong fleet was lured into the system, Skywalker, from Harbinger's bridge, led the ships from Bel Iblis' force as well as a group from the Smugglers' Alliance coalition in engaging the Yuuzhan Vong's Battle Group of Yun-Q'aah in one facet of the Battle of Ebaq. The battle ended in a victory for the New Republic forces, with Yuuzhan Vong Warmaster Tsavong Lah being killed during the fighting. At the end of the battle, New Republic Supreme Commander Sien Sovv made his report from the Harbinger.
Harbinger was later one of the multitude of warships that gathered near the planet Mon Calamari to aid the Galactic Alliance, the New Republic's successor state, in defending the ocean world from a massing Yuuzhan Vong armada in 29 ABY. At the edge of the Mon Calamari system, Harbinger and the Galactic Alliance forces encountered the enemy armada, which shaped itself like a yammosk, a tentacled creature with telepathic capabilities. After Galactic Alliance starfighters opened up holes in the arms of the armada that were formed by lighter Yuuzhan Vong vessels, Harbinger and the Super Star Destroyer Guardian pummeled the Yuuzhan Vong capital ships in the heart of the armada with their long-range weaponry through the opened firing lanes. As the fighting progressed, the Yuuzhan Vong armada deployed the shielding effects of its dovin basals between itself and Harbinger, Guardian, and the Viscount-class Star Defender Viscount, sparing the armada from the weapons of the trio of battleships.
In an effort to change the focus of the dovin basals, Galactic Alliance bombers infiltrated the armada, which forced the Yuuzhan Vong to defend themselves on a different front. Because of the resulting shift in defenses, Harbinger and Guardian were able to freely target the poorly defended arms of the armada with their weapons, destroying multiple coralskippers and picket ships. Not long after, the Yuuzhan Vong armada withdrew from the combat zone. Following the action in the Mon Calamari system, Bel Iblis and Harbinger accompanied a battle group that included the Imperial-class Star Destroyers Mon Mothma and Elegos A'Kla, as well as the MC80B Star Cruiser Mon Adapyne, to the Yuuzhan Vong–held world of Corulag to liberate it in a surprise attack. Traveling with the rest of the battle group from the planet Contruum, Harbinger decanted from hyperspace close to Corulag after the other three Galactic Alliance warships and rendezvoused with Elegos A'Kla.
With the help of the other capital ships, Harbinger boxed in the Yuuzhan Vong vessels, and the resulting crossfire destroyed many of the enemy coralskippers. During the fighting, Yuuzhan Vong–allied Peace Brigade TIE fighters launched from Corulag, and General Tycho Celchu, who was commanding Elegos A'kla, was assigned to deal with them, with Harbinger to aid Celchu if needed. In the end, Corulag was liberated from the Yuuzhan Vong, with Harbinger playing an important role in the fighting.
Commanders and crew
Behind the scenes
Harbinger first appeared in Walter Jon Williams' Destiny's Way, a 2002 installment of The New Jedi Order series of novels. Later appearing in the series' The Unifying Force, published in 2003 and written by James Luceno, Harbinger also received an entry in 2008's The Complete Star Wars Encyclopedia.