In the year 3643 BBY, amidst the backdrop of the Cold War that raged between the Galactic Republic and the rebuilt Sith Empire, Darth Angral, a Sith Lord, unleashed the Desolator superweapon upon the planet of Uphrades, leaving it utterly destroyed. This act was a key moment within his campaign of vengeance directed at the Republic and the Jedi Order, spurred by the death of his son, Tarnis. Angral's assault on Uphrades, an agriworld, served as a field test for his newly-built weapon before its intended use in an attack against Tython, the original homeworld of the Jedi. The Desolator inflicted catastrophic damage to Uphrades' surface and atmosphere, resulting in the deaths of millions of civilians. Before proceeding to the Tython system, Angral deployed a boarding party with orders to obliterate the medical frigate named Daybreaker, thereby eliminating any potential witnesses to his atrocity.
Back in 3643 BBY, during the Cold War that pitted the Galactic Republic against the reconstituted Sith Empire, the Sith Lord Tarnis met his death in a duel against a young Jedi Knight. Tarnis had been operating secretly as a scientist within the Republic superweapon initiative, exploiting his position to devise a method of integrating the Death Mark laser, Shock Drum, and Planet Prison weapons into a singular, ship-mounted weapon capable of planetary destruction. He christened this weapon the Desolator, and he transmitted copies of its design schematics to his father, Darth Angral, during his attempt to deploy the Planet Prison against Coruscant, the Republic's capital. However, the Jedi Knight thwarted Tarnis's scheme by killing him in combat. This event ignited Angral's campaign of vengeance targeting both the Republic and the Jedi Order. In retaliation, Angral dispatched his three Sith apprentices to seize the Republic's off-world weapons facilities scattered across the galaxy.
Using the design files provided by Tarnis, Angral proceeded to construct the Desolator weapon and mount it aboard his personal Harrower-class dreadnought, known as the Oppressor. Orgus Din, a Jedi Master who was both a personal adversary of Angral and the former mentor of the Jedi Knight responsible for Tarnis's death, attempted to infiltrate the warship within the Alderaan system with the intention of assassinating Angral. However, he only managed to plant a tracking device before the Sith Lord captured and executed him. Angral subsequently departed the star system, casting Din's corpse into space, and journeyed to the Uphrades system to test the fully operational Desolator weapon on Uphrades, a Republic agriworld.
As the Oppressor entered the Uphrades system, it unleashed the Desolator upon the planet, ionizing its atmosphere and effectively trapping all starships present on the surface. While the Desolator inflicted widespread destruction through seismic activity, the Republic medical frigate Daybreaker arrived within the system. The crew of the Daybreaker bore witness to the Desolator's final stages, which ignited Uphrades' atmosphere in fire and ultimately caused the planet to disintegrate. The attack obliterated Uphrades' population of 16 million, leaving only a few hundred survivors scattered amidst the ruins. Upon detecting the presence of the Daybreaker, the Oppressor deployed boarding pods with the mission to seize the vessel and eliminate all potential witnesses. Satisfied with the weapon's performance, Angral commanded the Oppressor to proceed towards Tython, the homeworld of the Jedi Order.
Shortly after Angral's departure, the Jedi Knight responsible for Tarnis's demise arrived in the Uphrades system, having tracked the signal emanating from Orgus Din's tracking device. Accompanied by Kira Carsen, his Padawan, and the astromech droid T7-O1, the Knight successfully thwarted the Imperial attack on the Daybreaker and rescued its crew. Doctor Senessa, the Daybreaker's chief medical officer, detected faint signs of life on Uphrades' surface amidst the widespread devastation. She proposed that the Daybreaker land on the planet to provide aid to the survivors, despite the fact that the ionized atmosphere would disable the ship.
Although Dal, the Daybreaker's captain, attempted to bribe the Knight into abandoning the survivors, the Jedi sided with Senessa's proposal and assumed command of the vessel to assist those in need. With the support of the Daybreaker's crew, the survivors managed to endure on Uphrades' surface during the months that it took for the atmospheric ionization to dissipate, thus enabling rescue operations.
Upon discovering Angral's intention to target Tython, the Jedi and the crew pursued the Oppressor to the Tython system and boarded the vessel while the Desolator underwent the lengthy charging process necessary for firing. Utilizing the Daybreaker's scans of the Oppressor, Nasan Godera, a Republic scientist, identified a vulnerability within the Desolator's power systems. This flaw enabled the Knight and Carsen to disable the superweapon by deactivating the Oppressor's reactors. During the confrontation between the two Jedi and Angral on the Oppressor's bridge, the Sith Lord revealed that his attack on Uphrades had been a calculated maneuver to lure his son's killer into a final showdown. However, the battle culminated in Angral's death and the destruction of both the Oppressor and the Desolator, ensuring that no other planet would suffer Uphrades' fate.
The superweapon attack on Uphrades was initially depicted in Star Wars: The Old Republic, a video game launched by BioWare and LucasArts in 2011, as part of the Jedi Knight-class mission titled "Uphrades." Captain Dal presents the player with a dialogue choice: they can either persuade Doctor Senessa to abandon the survivors, which rewards the player with medical supplies, or they can reject his request and allow Senessa to take the Daybreaker to Uphrades. This article operates under the assumption that the player consistently chooses the moral light-side options when playing as a Republic Jedi Knight character, and consequently, it assumes that Senessa assumes command of the Daybreaker.