The Steadfast, a Resurgent-class Star Destroyer belonging to the First Order Navy, functioned as the flagship for both Supreme Leader Kylo Ren and Allegiant General Enric Pryde. Having been commissioned in 28 ABY, its designation was a tribute to the earlier Steadfast, an Imperial-class Star Destroyer on which Pryde had served until it met its destruction during the Galactic Civil War. During the First Order-Resistance War, Ren and General Armitage Hux relocated from the Finalizer to the Steadfast. The Steadfast also served as the base of operations for the First Order Supreme Council, an advisory group of high-ranking First Order officers established by Ren.
Throughout the final days of the galactic conflict, the Steadfast journeyed to various locations, including Mustafar, Pasaana, Kijimi, and the Sith world of Exegol. On Kijimi, the Resistance mounted an infiltration of the Steadfast, which led to the liberation of Chewbacca and Pryde's execution of Hux for providing aid to the enemies of the First Order. After Ren renounced the dark side of the Force, Darth Sidious, the resurrected Galactic Emperor, summoned Pryde to Exegol, where the Sith Eternal's fleet of Xyston-class Star Destroyers, known as the Final Order, was poised to deploy across the galaxy.
In 35 ABY, during the Battle of Exegol, the Resistance brought about the destruction of the Steadfast as it was attempting to guide the Sith fleet through Exegol's atmosphere. Both Pryde and Admiral Frantis Griss perished when the bridge was destroyed in an explosion, and the remaining Sith Star Destroyers were subsequently eliminated by the combined might of the Resistance navy and the Citizens' Fleet.
The Steadfast represented a Resurgent-class Star Destroyer, embodying the next evolution of warship within the Star Destroyer lineage, meticulously crafted by Kuat-Entralla Engineering for the First Order. Starships of the Resurgent-class drew inspiration from the Imperial-class Star Destroyers of the Imperial Era. While maintaining the iconic "wedge-shaped" silhouette reminiscent of the Galactic Empire's naval vessels, the Resurgent-class prioritized enhanced efficiency. Consequently, a First Order Star Destroyer boasted more sophisticated weaponry compared to its Imperial predecessor, featuring kyber crystal-powered turbolasers. Furthermore, it surpassed the Imperial-class in the swift deployment of starfighters, necessitating the inclusion of hangars to accommodate the required complement of TIE/fo space superiority fighters. The Steadfast was designated as the command ship for a battlegroup, while also functioning as the flagship of the entire First Order Navy.
The command echelon comprised members of the First Order High Command, including Allegiant General Enric Pryde and the senior fleet officer, Admiral Frantis Griss. Griss, as the commanding officer, exercised control over the Steadfast and its accompanying support ships within the battlegroup. Griss operated under the authority of Pryde, whose military rank granted him jurisdiction over both the First Order Army and Navy. Additional high-ranking First Order military figures stationed aboard the Steadfast included General Bellava Parnadee, General Domaric Quinn, and General Amret Engell. The crew of the Steadfast consisted of both young First Order officers and older officers, some of whom reported directly to members of High Command, such as Commander Masir Trach, Lieutenant Lanzora Garan, and intelligence officer Tishra Kandia. Similar to the Finalizer and other Star Destroyers in the First Order fleet, the Steadfast carried a contingent of First Order stormtroopers.
Supreme Leader Kylo Ren shifted his headquarters from the Finalizer to the Steadfast, which subsequently became known as "Ren's Destroyer," after he ascended to the position of Snoke's successor, following extensive damage sustained by the Finalizer in the Battle of Batuu. Ren also mandated the transfer of General Armitage Hux to his new flagship, unwilling to leave the general unsupervised due to the animosity that had developed between them as rivals for power. Although Hux became part of the Steadfast's command crew, his authority was superseded not only by Supreme Leader Ren but also by Allegiant General Pryde. Nevertheless, Hux's presence onboard the Steadfast fostered discord among its crewmembers, who found themselves caught in the rivalry between Hux and Pryde. Commander Trach, also transferred from the Finalizer, focused on his assignments to avoid taking sides in the conflict between the senior officers.
One of Ren's initial actions as Supreme Leader involved the establishment of the First Order Supreme Council, a cabinet comprising Pryde, Hux, and other High Command officers serving within the Steadfast's command crew. As a result, the Steadfast featured a conference room specifically for the Supreme Council's meetings. The Star Destroyer also housed the Supreme Leader's private suite, where Ren kept the mask of his deceased grandfather, the Sith Lord Darth Vader, atop a pillar of obsidian, along with holding cells used for the detention and interrogation of prisoners. One such cell was designated Interrogation Six.
During the New Republic Era, the Steadfast was built as one of the new Star Destroyers for the First Order, violating the Galactic Concordance between the Old Empire and the New Republic. Enric Pryde, a former Imperial officer who had served in the Galactic Civil War, was given command of the Steadfast by Supreme Leader Snoke in 28 ABY. The Steadfast shared its name with the Imperial Star Destroyer that Pryde had been stationed on until it was destroyed at the Battle of Jakku.
The vessel's commander was not involved during the early phase of the First Order-Resistance War. Snoke had placed Pryde in command of the First Order's reserve forces, before Snoke was killed and replaced by his apprentice, the dark warrior Kylo Ren. In addition to bringing the reserve forces into the main conflict, the new Supreme Leader promoted Pryde to Allegiant General, giving him authority over the entire First Order military.
The Steadfast took over the role of Ren's flagship during his time as Supreme Leader, replacing the Finalizer, which had been damaged in a battle with the Resistance above the planet of Batuu. By this point, Admiral Griss, a trusted associate of Pryde, was the Star Destroyer's commanding officer, although Ren and Pryde still had overall authority over the flagship. Haunted by his late uncle, Jedi Master Luke Skywalker, Ren revisited several locations from his past in an attempt to locate and destroy his former mentor. Taking the Steadfast to Crait, Ren went to the planet's surface but found no trace of Skywalker at the site of their final confrontation. After his fruitless search, Ren ordered General Armitage Hux to use the Star Destroyer's batteries to obliterate the ruins of Skywalker's Jedi Temple on Ossus.
Following the announcement of Galactic Emperor Darth Sidious in 35 ABY, Ren took the Steadfast to Mustafar, where he recovered the Sith wayfinder that had once belonged to his grandfather Darth Vader. The Steadfast remained in orbit around Mustafar while Ren, along with Generals Pryde and Hux, and a group of stormtroopers, carried out his mission to locate Exegol.
After confirming that the Emperor was on Exegol, Ren returned to the Steadfast with the Knights of Ren. He called a meeting of the Supreme Council to discuss his plans for the First Order, which included taking control of the Xyston-class Star Destroyers that made up the Sith Eternal fleet known as the Final Order. While General Quinn questioned Ren's alliance with a group of Sith cultists, Pryde saw advantages to reinforcing the First Order with the forces of the Sith Eternal, specifically the exponential increase in the First Order's ability to project its military power across the galaxy. Ren executed Quinn for continuing to question his agreement with Sidious to prevent anyone from finding out what his grandfather's master wanted, silencing any further debate on the topic and, certain in his future as the new Emperor of a true Empire ruling over the galaxy, directed the Supreme Council to continue suppressing all worlds that defied them.
The Steadfast continued to serve as the Supreme Leader's flagship during his personal mission to find and capture Rey, the Jedi apprentice of Ren's mother, General Leia Organa of the Resistance. Using his connection with Rey, Ren seized a husk necklace from the scavenger, causing the item to physically transfer to his location on the Steadfast through the Force. An analysis of the necklace by Officer Tishra Kandia connected it to the planet Pasaana. Although Ren's troops failed to capture Rey, they apprehended one of the scavenger's companions, Chewbacca, with the help of the Knights of Ren. The Wookiee prisoner was escorted by stormtroopers to the Steadfast and, after being presented to Allegiant General Pryde by General Hux, was taken to Interrogation Six.
Ren personally interrogated Chewbacca, whom the Wookiee had once known as Ben Solo, the son of his deceased friend, Han Solo. Having long convinced himself that neither Chewbacca nor his family cared about him, Ren tortured the Wookiee, using the dark side of the Force to probe his mind for information about Rey. Instead, Ren discovered memories of his past where as a child he regarded Chewbacca as an uncle. Ren, struggling to suppress the light side of the Force within him, left Chewbacca in the interrogation cell. His belongings were taken to the Supreme Leader's quarters in the Steadfast, including the dagger that had been discovered in the Pasaana desert by Rey's team.
The Steadfast was taken to the occupied world of Kijimi after the Knights of Ren tracked Rey's team to Kijimi City. Ren gathered his soldiers in the city to search for the scavenger while the Steadfast orbited the planet. Because of its proximity, Rey sensed Chewbacca's presence through the Force and realized that her friend was being held captive in Ren's Star Destroyer. Using a First Order Captain's Medallion, obtained from Zorii Bliss, an associate of the former smuggler Poe Dameron, Rey and her companions infiltrated the Steadfast to rescue Chewbacca and retrieve Ochi's dagger. FN-1226 and FN-0606 confronted the group, only to fall under Rey's influence through her use of the Jedi mind trick ability, which forced the stormtroopers to provide the Resistance with directions to Chewbacca's holding cell. Rey directed her friends to rescue the Wookiee while she recovered the dagger from Ren's chambers.
A firefight broke out in the Star Destroyer's corridors shortly after Dameron and Finn released Chewbacca from his cell. Although the Resistance fighters killed numerous stormtroopers during their escape attempt, they were eventually overwhelmed and surrounded by the First Order soldiers, forcing them to surrender. Allegiant General Pryde ordered their immediate execution, but the firing squad was killed by General Hux, who had secretly become a spy for the Resistance in order to undermine Ren's reign as Supreme Leader. Hux guided Rey's team to the hangar where their starship, the Millennium Falcon, was stored.
Meanwhile, Rey located Chewbacca's belongings along with Ochi's dagger after finding Ren's quarters. At that point, she reconnected with Ren through their bond in the Force, which allowed them to communicate without seeing each other's surroundings. Determined to convert Rey to the dark side, Ren began to reveal the full truth of Rey's origins, causing the young apprentice to attack him with the Skywalker lightsaber. A lightsaber duel began between them, causing items to transfer between their separate locations, including the helmet of Ren's grandfather. The Sith relic's sudden appearance on Kijimi confirmed Rey's location aboard the Steadfast to Ren, who ordered his forces to put the flagship on lockdown to prevent Rey from escaping.
Ren confronted Rey after returning to the Steadfast in his personal TIE/wi modified interceptor. A group of stormtroopers gathered in the hangar where Rey and Ren were located. Armed with the knowledge of Rey's secret lineage, Ren revealed to the scavenger her biological relationship with Sidious, that her father was the Emperor's son, making her his granddaughter. Ren also disclosed the nature of their own relationship as a dyad in the Force, a connection unknown to Rey's grandfather. He urged her once more to join him, declaring that together they would kill Sidious, take the Throne of the Sith, and rule the galaxy as a dyad. Rey refused his offer and rejoined her friends on the Millennium Falcon. A number of stormtroopers were injured and killed by the Falcon's engines, which also damaged the Steadfast's hangar, neither of which concerned Ren as he remained fixated on his objective of turning Rey.
Sidious contacted Ren through the Force; suspecting Ren of duplicity, he warned the Supreme Leader that he could turn the Sith fleet against him. Ren assured the Sith Lord that he would not allow Rey to become a fully-trained Jedi. He departed from the Steadfast again, traveling to Kef Bir in the Endor system for a final confrontation with the scavenger. Meanwhile, Hux attempted to convince Pryde that he had been captured by the Resistance, who forced him to aid their escape from the Steadfast. Seeing through Hux's attempt at deception, the Allegiant General personally executed the younger officer for trying to sabotage Supreme Leader Ren's war efforts, and ordered Lieutenant Garan to contact the Supreme Leader for him so he can reveal the spy's fate.
Kylo Ren was redeemed, returning to the light side of the Force as Ben Solo. As a result, General Pryde once again became a loyal servant to Darth Sidious. The First Order and the Sith Eternal joined forces to conquer the galaxy, although some First Order officers had concerns about their alliance with a group of Sith cultists, preferring technology and logic over the Sith Eternal's reverence for the dark side of the Force but didn't question their ways to keep themselves safe from the wrath of the Sith.
Under the direct command of the Allegiant General, the Steadfast served as the leading capital ship of the Sith fleet on Exegol, and was armed with the newly introduced Sith troopers and Sith Jetpack Troopers.
During the Battle of Exegol, the Steadfast noticed that a Resistance ground team was planning on blowing up the navigation tower to prevent the Sith fleet from leaving Exegol, so General Pryde ordered that they switch over the source of navigation signal from that tower to one of the Steadfast's towers.
The Resistance ground team landed on the Steadfast and engaged the ground forces of the Sith Eternal, until Finn and Jannah destroyed the ship, taking out the command deck with one of the ship's own hotwired laser cannons, decimating the bridge and killing its officers, including Pryde and Admiral Griss. The Steadfast then crashed onto the surface of Exegol and exploded, but not before Finn and Jannah were rescued by the Millennium Falcon.