This pivotal assault marked the concluding engagement of the Sith–Imperial War. In the year 127 ABY, subsequent to the failure of the Ossus Project—an initiative aimed at the restoration of planets devastated during the preceding Yuuzhan Vong War—the Galactic Empire formally declared hostilities against the Galactic Alliance. One year into this conflict, the Sith Order materialized, extending an offer of alliance to the Empire to aid in the subjugation of the Alliance's Jedi. Reinforced by the Sith, the Empire witnessed the Alliance's capitulation in 130 ABY. Post-surrender, the Dark Lord of the Sith, Darth Krayt, arrived on Coruscant, where he confronted a decoy of Emperor Roan Fel during a session with the Moff Council. Mistakenly believing the decoy to be Fel himself, Krayt asserted that his Sith Order had been instrumental in securing victory and now sought his due—Fel's demise. Krayt and his Sith eliminated the Emperor's guards and the decoy, after which Krayt proclaimed himself the new emperor.
Around the time of 127 ABY, the Yuuzhan Vong's planetary restoration endeavor—a project designed to revitalize planets damaged in the Yuuzhan Vong War a century prior—was initiated. However, numerous complications arose, leading to various mutations on the planets involved in the project. Incensed by these developments, the Galactic Empire—which harbored lingering resentment towards the Yuuzhan Vong for the war—declared war against the Galactic Alliance, which had endorsed the Ossus Project at the urging of the New Jedi Order.
The ensuing conflict initially favored the Alliance, as the Jedi proved to be a significant asset. After a year, the Sith Order emerged, offering their assistance to the Imperial forces. The Empire accepted their offer, and with the help of the Sith, the momentum began to shift. However, unbeknownst to Emperor Roan Fel, the Sith had orchestrated the failure of the Ossus Project and had previously approached Grand Admiral Morlish Veed and Moff Nyna Calixte with a proposal for an alliance. They had also pledged to overthrow Emperor Fel and replace him with a more formidable leader. Veed, assuming that the Sith were referring to him, accepted their offer along with his lover Calixte. They subsequently manipulated the Moff Council into accepting the Sith's terms when the opportune moment arrived.
Following the Alliance's surrender in 130 ABY, Darth Maladi convened with Calixte and Veed, who had recently been appointed as High Moff, aboard Veed's command ship, the Imperious. She revealed that the time had come to depose Fel from the throne, and they planned to execute this during a meeting that Fel had scheduled with the Moffs in the coming days. However, Calixte experienced a change of heart and feared that the Sith would instead install their leader, Darth Krayt, as emperor. She secretly warned Fel, informing him of the Sith's intention to assassinate him. Fel decided to use a body double in his place at the meeting.
The meeting commenced as planned, with Fel and the Moffs deliberating the terms of the Alliance's surrender. Midway through the conference, Darths Krayt, Maladi, Nihl, and Wyyrlok made their entrance. Fel's decoy inquired about the Sith's desired compensation for their assistance in the war, to which Krayt responded that he sought the Emperor's life. Fel's Imperial Knight escorts moved to shield Fel's double; however, they proved to be no match for the Sith. Mohrgan Fel and Fel's three additional guards were swiftly slain. Krayt then eliminated Fel's decoy and declared himself the new Emperor. With the war concluded, Krayt proclaimed that he would now implement his grand vision.
Krayt swiftly discerned that the individual he had slain was not Fel, as the former Emperor possessed proficiency in the Force and lightsaber combat and would have undoubtedly retaliated, whereas the imposter Fel had not even attempted to resist. Krayt declared Fel to be a fugitive from Imperial justice, and his agents initiated a search for him. Fel and the faction that remained loyal to him spent the ensuing years conducting hit-and-run attacks on Krayt's Empire. Seven years hence, Fel remained at large, much to Krayt's dismay.
In the meantime, shortly after the murder attempt, Maladi visited Calixte at her residence and accused her of informing Fel about the impending attack. Before departing, Maladi threatened Calixte, informing the Moff that she was now in service to the Sith Lord.
The assault on Emperor Fel is initially depicted in the inaugural edition of Star Wars: Legacy, Broken, Part 1. It is subsequently featured in a flashback in Legacy (2006) 8, which portrays a segment of the assault from Calixte's perspective. The Essential Atlas erroneously places the assault in the year 137 ABY.