The Eternal Throne, situated atop the Spire overlooking Zakuul's atmosphere, served as the seat of power for the Eternal Empire's Emperor. Over time, the name "Eternal Throne" became synonymous with governing the Eternal Empire and, later, after the Galactic War, the entire galaxy.

Emperor Valkorion of Zakuul, after locating the dormant Eternal Fleet using Force visions from the Scions of Zakuul, realized he needed a way to command it. He gathered Zakuul's most brilliant minds and tasked them with constructing the Eternal Throne, a project that spanned generations. The Throne's construction incorporated technology from Iokath, the Eternal Fleet's world of origin, mirroring the thrones used to control the Six Gods there.
Completed more than a century before 3636 BBY, the Eternal Throne was placed in Valkorion's throne room, located at the summit of the Spire, Zakuul's highest point. The specific mechanism by which the Throne controlled the Eternal Fleet remained a secret known only to Valkorion, who eventually shared it with his offspring: Arcann, Thexan, and Vaylin. A hyperwave relay station, situated ten kilometers beneath the Spire and powered by two hundred generators tapping into Zakuul's core, connected to the Throne. This gave the occupant access to the GEMINI frequency, allowing them to communicate with and direct the GEMINI units operating the Eternal Fleet.
Upon Vaylin's return from Nathema, she entered the Eternal Throne room and confronted Valkorion, who was seated with her brothers. She expressed resentment for being left there. Valkorion responded by stating that she belonged by his side and presented her with her lightsaber. When Vaylin ignited the weapon, Arcann and Thexan moved to protect their father, but Valkorion ordered them to stand down. Vaylin, to their relief, deactivated her lightsaber and knelt before Valkorion, acknowledging his authority.

After the Eternal Empire raids, Valkorion's twin sons brought him trophies of lightsabers and banners from their defeated enemies, presenting them at the foot of the Eternal Throne. Valkorion's silence and indifference enraged Arcann, who lunged at his father with his lightsaber, intending to kill him. Thexan used the Force to pull his brother back mid-air. Consumed by anger and the dark side, Arcann engaged Thexan in a brief but intense lightsaber duel, resulting in Thexan's death. As Arcann regained his senses, horrified by his actions, Valkorion approached him, seemingly unmoved, and instructed Arcann to follow him.

Soon after, Darth Marr led a joint Republic–Imperial task force into the Unknown Regions. As they neared Zakuulan space, Arcann informed his father, who was on the Eternal Throne, of their arrival. Valkorion, already aware of their presence, deployed the Eternal Fleet. Marr's expedition was destroyed, but Arcann's forces captured Marr and a second figure, bringing them to Zakuul and before the Eternal Throne. The prisoners recognized Valkorion as the former Sith Emperor Vitiate. Valkorion offered to share his power with them but killed Marr when the Sith Lord attacked. Vaylin ordered everyone to leave the Eternal Throne room, leaving only Arcann, Valkorion, and the remaining prisoner, to whom Valkorion repeated his offer. Arcann, taking advantage of Valkorion's focus on the Outlander, attempted to strike his father down again. In the ensuing confrontation, Valkorion's physical body was mortally wounded, but his spirit, refusing to die, entered the Outlander's body seeking a new host.

Sensing his father's spirit within the Outlander, Arcann ordered the Outlander to be immediately frozen in carbonite. He then claimed the Eternal Throne, declaring himself the new Eternal Emperor and initiating a full-scale conquest of the Core Worlds. With the Eternal Throne and the Eternal Fleet at his disposal, Zakuul gained naval dominance over both the Republic and the Sith Empire, leading them to sue for peace within a year. Emissaries from both sides were brought before the Eternal Throne on Zakuul. Vaylin was present when Republic Senator Evran and Sith Empire Dark Councillor Darth Vowrawn pledged their allegiance to Arcann. After they departed, she sensed an unseen presence in the room, but when Arcann questioned her, she remained silent, instead stabbing the empty space with her lightsaber.

Five years after Valkorion's death, the Outlander was freed from their carbonite prison and escaped with allies aboard a stolen shuttle, crashing in the Endless Swamp. Vaylin informed Arcann in the Eternal Throne room, who deduced that the damaged shuttle could only have landed in the Endless Swamp and dispatched skytroopers to search for metallic sensor readings. However, the dissidents found the Gravestone, a legendary starship capable of overpowering the Eternal Fleet, and launched it into the air. From the Eternal Throne, Arcann ordered the Eternal Fleet to destroy the vessel as it attempted to leave Zakuul, only to witness a single omnicannon blast from the Gravestone obliterate over two dozen Eternal Fleet warships before it jumped into Hyperspace.

Vaylin confirmed that the Outlander was aided by their mother, Senya Tirall, who had betrayed her children. Vaylin speculated whether Senya knew about Valkorion's survival within the Outlander and was trying to restore his rule. Arcann dismissed the idea, vowing that their mother would either return or face the consequences. Soon after, the Outlander and Senya returned to Zakuul and were seen in the Old World. When Vaylin told Arcann, he wondered why their enemies would return after escaping. From the Eternal Throne, he publicly warned the citizens of the Old World to be vigilant for the fugitives.

Following the Battle of Asylum, Arcann sat brooding on the Eternal Throne, frustrated that Valkorion was plotting against his own children. Vaylin revealed that she had told Senya during their duel on Asylum that Arcann had killed Thexan, contrary to the public announcement that he died in battle during the Core Worlds conflict. Arcann, feeling sentimental, remarked that Thexan should be alive, ruling the Empire alongside his brother and sister as it was intended. Despite Arcann's widespread search for the Gravestone and the Outlander, Vaylin and the Eternal Fleet patrols were unable to locate them for weeks. Losing patience, Arcann ordered Vaylin to bombard one inhabited world in five different sectors, hoping to either draw the Outlander out of hiding or incentivize someone to reveal their location.

The Outlander had established an Alliance to oppose Zakuul. Arcann expressed his frustration to Vaylin about Valkorion's refusal to confront him directly. Vaylin suggested that Valkorion was punishing Arcann for usurping his throne, but Arcann argued that their father had always been emotionless, even when Arcann murdered Thexan. When Vaylin became nostalgic about their late brother, Arcann asked if he still had her support, which Vaylin confirmed. After Vaylin returned to Zakuul from Vandin, Arcann interrupted her revenge fantasies against Senya by asking if she remembered their mother from their childhood. Vaylin refuted her belief that Senya hated her for being more powerful, and Arcann agreed that Senya never truly understood her children or their father. While Vaylin reminded him that the Outlander and Senya had stolen their valuables, which could inspire other worlds to rebel, Arcann reassured her that the riches could be replaced and fear of his power would prevent further uprisings.

From the Eternal Throne, Arcann and Vaylin watched a holographic report of a Mandalorian army assaulting an Eternal Empire weapons factory on Darvannis. Vaylin proposed sending the Eternal Fleet to annihilate the Mandalorians, but Arcann, content to watch their enemies struggle, declined. As the battle progressed and the Mandalorians gained the upper hand, Arcann realized that the Mandalorians were inspired by a cause they believed in and that the Outlander was on Darvannis with them. They received a distress call from a GEMINI captain revealing that the Outlander and Senya were attempting to commandeer an Eternal Fleet warship. Arcann, accompanied by Vaylin, took his Eternal Flagship and a significant portion of the Eternal Fleet to intercept his enemies.

While the siblings were away from Zakuul, an advanced artificial intelligence named SCORPIO uploaded herself into the GEMINI frequency, intending to seize the Eternal Throne. Using the frequency, SCORPIO directed Eternal Empire skytrooper forces to attack and eliminate the Knights of Zakuul guarding the Eternal Throne. SCORPIO then constructed a new body for herself and installed herself directly onto the Eternal Throne. She assumed control of the Eternal Fleet but deliberately left a substantial detachment under Arcann's command. SCORPIO then manipulated her enemies into destroying each other, revealing the location of the Alliance base on Odessen to Arcann, correctly predicting that he would prioritize going after the Alliance and its Commander over her.

Arcann was defeated and removed from power. SCORPIO used the Eternal Throne to reprogram all GEMINI units, granting her "children" free will. Upon returning to Zakuul, Vaylin fought her way through SCORPIO-controlled skytroopers in the Eternal Throne room. However, she sheathed her lightsaber after SCORPIO ordered her droids to cease firing. SCORPIO greeted Vaylin and explained that she had only taken the Eternal Throne to liberate the GEMINI droids. Vaylin declared herself more deserving of the Eternal Throne's power than Arcann. Surprised that SCORPIO did not want to control her children, Vaylin agreed that the ability to choose made them stronger. SCORPIO then willingly relinquished the Eternal Throne to Vaylin, offering to stay and advise the new Empress of Zakuul on how to destroy their enemies.

Vaylin tracked Senya and Arcann to Voss and invaded the planet with the Eternal Fleet to force them out of hiding. From the Eternal Throne, Vaylin watched as her forces landed in and captured the capital city of Voss-Ka, after which she gleefully ordered the planet to be burned to ashes. As the fighting continued, SCORPIO detected the presence of Mandalorian forces in Voss-Ka, indicating that the Outlander, with the spirit of Valkorion still inside them, was also on the planet. Vaylin located all three of her family members inside the Shrine of Healing and ordered the Eternal Fleet to bombard it in an attempt to kill them all. However, before the Eternal Fleet ships could scorch the planet's surface, the Imperial fleet arrived, causing the GEMINI units to retreat from the battle. Vaylin was angered by their unauthorized retreat, but SCORPIO pointed out that the GEMINI had simply made a choice she disliked and urged the Empress to focus on the bigger picture. Simultaneously, Valkorion decided that his children were unworthy of the Eternal Throne and made it clear that he wanted the Outlander to take his place.

Shortly after, news arrived from Dromund Kaas that the Outlander had died. Although Vaylin could sense Valkorion's presence and knew this was not true, SCORPIO noted that the resulting chaos presented the perfect opportunity to strike against the Alliance and set up a trap. SCORPIO, Vaylin, and a contingent of Knights of Zakuul and Horizon Guard took control of the Gravestone. However, SCORPIO betrayed Vaylin and took the Gravestone and the Eternal Fleet to Iokath. Vaylin, determined to ensure her fleet obeyed her orders without question, brought a Purifier droid from Iokath back to Zakuul. She connected it to the Eternal Throne, and the purifier used the connection to restore every GEMINI unit to its original settings. Vaylin tested this by ordering one ship in the fleet to destroy another. After it obeyed without hesitation, Vaylin expressed satisfaction and destroyed the Purifier.

Vaylin was killed by the Outlander during the assault on Odessen, leaving the Eternal Throne vacant. Without orders, the GEMINI captains went rogue, reverting to their most basic function: exterminating all complex life in the galaxy. Eternal Fleet warships began bombarding heavily populated worlds, including Zakuul itself, and established a blockade around the Spire, protecting the Eternal Throne with a ray shield. The Alliance leadership traveled to Zakuul, and the Outlander, Senya, and a redeemed Arcann made their way to the Spire. They reached the Eternal Throne room, where Arcann was overwhelmed by the sight of his former Throne and lamented the millions of deaths he had caused while sitting on it. Senya reassured him that he had become a better person. Arcann offered the throne to the Outlander as atonement for his past actions. The Outlander claimed the Eternal Throne and sent a signal to the Eternal Fleet, which immediately went silent.

However, Valkorion's spirit then revealed his true intention: to erase the Outlander's mind and take possession of their body. While the Outlander fought back within their mind, skytroopers breached the Throne room. Arcann and Senya held them off until Senya instructed Arcann to use Dramath's holocron to join the Outlander in the fight against his father. Meditating on the holocron, Arcann entered the Outlander's mind, where they were joined by Vaylin's spirit. The Outlander used Valkorion's manipulation of Vaylin against him, finally ending his millennia-long existence. Back in the Eternal Throne room, Arcann noted that he no longer felt his father's presence and believed he could not return to the world of the living. Senya initiated a holo-broadcast for the new owner of the Eternal Throne, who addressed the galaxy and proclaimed the era of the Eternal Alliance. In the following days, the Alliance moved the Eternal Throne from the Spire to Odessen, installing it in the Alliance base.

Seeking revenge on the Alliance for ending Zakuul's golden age, former Horizon Guard Vinn Atrius launched a campaign with the ultimate goal of awakening Zildrog, an ancient superewapon from Iokath buried on Nathema. Under the supervision of GEMINI 16, the Order of Zildrog excavated and reactivated the superweapon. Zildrog revealed itself to be connected to the Gravestone, which it remotely commandeered while it was parked on Odessen. Zildrog moved the Gravestone into Odessen's orbit and repeatedly fired the omnicannon at the Eternal Fleet, which was defenseless without orders from the Eternal Throne. Zildrog then targeted Odessen itself, but its core was destroyed on Nathema, triggering the self-destruct of both the Gravestone and the Eternal Throne, resulting in a significant loss for the Eternal Alliance.

The Eternal Throne plays a prominent role in the Knights of the Fallen Empire and Knights of the Eternal Throne expansions for Star Wars: The Old Republic. The player gains control of the Eternal Throne in Chapter IX of the Knights of the Eternal Throne campaign.
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In a light side choice, if the player chooses to lead the Eternal Alliance as a peacekeeper, the Throne's control systems are integrated into the updated Alliance war room. Conversely, in a dark side choice, if the player decides to become the new Emperor/Empress, the Eternal Throne is placed in a throne room resembling the one in the Spire on Zakuul. [8]
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Furthermore, if the player has consistently made light side choices, they will be accompanied into the Eternal Throne room by Senya Tirall and a redeemed Arcann. If the player chose to kill both Senya and Arcann (in Chapter I and Chapter VI, respectively, of Knights of the Eternal Throne), they will instead be accompanied by Theron Shan and Lana Beniko. [8]