Darth Marr, a Human male who rose to become a Dark Lord of the Sith, served on the Dark Council of the re-established Sith Empire. He was a key figure during the Great Galactic War, the Cold War, and the Galactic War against the Galactic Republic. Born in 3702 BBY, this formidable warrior and staunch defender of the Empire ascended to the Dark Council in his early twenties. As the leader of the Sphere of Defense of the Empire, he successfully repelled entire armies and thwarted Republic offensives throughout the Great War. By 3653 BBY, when the war concluded, Marr had elevated Darth Lachris to the status of Sith Lord and was one of only seven Councilors remaining. Throughout the Cold War, he dedicated himself to bolstering Imperial defenses and preparing for future conflicts, while also distancing himself from the treacherous power struggles that weakened the Council and the Empire.
With the outbreak of renewed hostilities with the Republic, Darth Marr witnessed the Dark Council's ranks diminish due to both enemy action and internal strife. Following the deaths of Darth Baras and Darth Decimus, who headed the Spheres of Military Offense and Military Strategy respectively, Marr assumed a leading role alongside fellow Councilors Darth Mortis and Darth Ravage, effectively becoming the sole commander of the Imperial Military. Consequently, he was widely regarded as the Empire's de facto leader until his death.
Born in 3702 BBY within the territories of the revived Sith Empire, the Human male who would become known as Darth Marr possessed a past shrouded in mystery. After the Sith Lord rose to power, those who knew of his history refused to divulge any information. Trained as a Sith Warrior, Marr, like many powerful Sith, adopted an armored battle suit. His armor and expressionless mask were intentionally designed to evoke the image of a monstrous Sithspawn creature. Shortly before joining the Sith Empire's ruling Dark Council—a position he attained around the start of the Great Galactic War against the Galactic Republic in 3681 BBY—Marr recovered the lightsaber belonging to the ancient Sith Lord Tulak Hord on the planet Dromund Fels. As with the other eleven Council members, Marr oversaw one of the Empire's Spheres of Influence; in his case, it was the Sphere of Defense of the Empire.

Around 3678 BBY, Darth Marr, along with several other Dark Councilors, confronted the Sith Lord Calypho on Korriban and arrested him for heresy just as Calypho's apprentice, Teneb Kel, returned from a mission into the planet's ancient tombs. Kel was permitted to participate in the Imperial offensive on Begeren, but following the Invasion of Begeren, he was also taken into custody. Darth Marr led celebratory parades through the streets of Kaas City on the Imperial capital of Dromund Kaas to mark the victory. Subsequently, he attended a Council meeting in their chamber beneath the Imperial Citadel. There, Kel was brought before Darth Marr and the other Dark Councilors and commanded to kill Lord Calypho. Marr observed that the young Sith drew strength from his fear, prompting another Councilor to ridicule Kel for not drawing on his anger. When a Councilor stopped the battle before Calypho's death, Imperial Guardsmen escorted the Sith away for torture, and Marr reminded the apprentice that he was not special, as his master had made him a disgrace.
Nevertheless, Marr and several other Councilors recognized Kel's potential as a weapon. Marr presented a hologram of Kel's target: Exal Kressh, the wayward apprentice of the Sith Emperor. Dismissing Kel's questions, the Dark Councilor informed the young Human that his place in the Empire would be reevaluated if he succeeded in his mission. He then brought Kel before the Emperor himself, bowing deeply as the Sith ruler informed Marr's chosen assassin that Kressh could be found in the Lenico system. Kel ultimately tracked down and killed Kressh on Korriban, but not before discovering the Emperor's plan to create his Children—extensions of his will intended to spread his influence secretly throughout the galaxy. During his report to the Dark Council, Kel refused to submit to their authority, prompting Darth Marr to unleash a storm of Force lightning as a threat. However, Kel persuaded the Council to accept his offer: in exchange for information on the Emperor's plans, the Dark Council would grant him the rank of Sith Lord and the title of Darth Thanaton.

As the Great Galactic War raged on, Darth Marr gained a formidable reputation among both the Republic and the Empire. He fearlessly led Imperial forces into battle and defended the Empire's conquests against Republic counterattacks. In 3660 BBY, Darth Marr successfully repelled a Republic offensive against Korriban, and he inflicted another significant defeat on the enemy when the Republic attempted to strike at Ziost. By the war's end, Marr had trained his own apprentice, Darth Lachris, a fierce warrior who, like her master, understood the harsh realities of politics. He also took an interest in certain Force-sensitive individuals within the Empire, such as the brother of Talos Drellik, often personally escorting them to the Sith Academy on Korriban. Known throughout the Republic as the masked Dark Councilor who had defeated entire armies and halted numerous Republic assaults, Marr was one of only seven Dark Council members still alive when the Treaty of Coruscant ended the war in 3653 BBY.
During the following decade, known as the Cold War, Darth Marr dedicated himself to preparing the Empire for future conflicts. He strengthened Imperial defenses and exerted control over his Sphere of Influence to ensure the Republic would find no weaknesses in the Empire's armor. After Moff Xerxian failed to suppress an uprising on the Imperial-conquered world of Sullust, he was summoned for a private audience with Darth Marr. Following the meeting, Xerxian dictated a letter of resignation and then took his own life, leading to widespread speculation about what had transpired. The most common rumor suggested that the Sith Lord had removed his mask, allowing Xerxian to see his supposedly disfigured face.

When the prototype Imperial warship Voidstar was rediscovered, Marr ordered an Imperial strike team to reclaim it before the Republic could seize the derelict dreadnaught. Governor Lysennius Melchiro's persistent failure to quell the Balmorran resistance on the conquered planet Balmorra eventually led to his removal by the Dark Council, and Darth Lachris, Marr's former apprentice, was chosen to replace him. After a Republic assault on the world failed, Lachris' forces captured a large number of Republic troopers and several Jedi. The Sith Lord then delivered the captive Jedi to Darth Marr so that he could attempt to break them and convert them to the dark side of the Force.
In 3640 BBY, Darth Tormen presented Darth Marr with the body of Supreme Chancellor Dorian Janarus during a special session of the Council. Tormen's bounty hunter had assassinated the Chancellor aboard his personal cruiser Founder during the Battle of Corellia. Marr expressed his satisfaction with Tormen's actions and indicated his interest in hiring the bounty hunter should the need arise. Marr's support angered his fellow Dark Councilor Darth Decimus, whose Sphere of Military Strategy had planned the Imperial invasion of Corellia and who was personally overseeing the battle.

Shortly thereafter, Darth Marr and the other Councilors were summoned to Korriban by Darth Baras. Darths Hadra and Acharon were forced to attend via hologram alongside Decimus, as they had joined Decimus in overseeing the Imperial offensive on Corellia. At the meeting, Baras attempted to declare himself the Voice of the Emperor—the individual through whom the Emperor delivered his commands—and thus seize control of the entire Empire. However, his declaration was interrupted by the arrival of Darth Vowrawn and Baras' former apprentice. The Sith Warrior had been appointed as the Emperor's Wrath, and Marr rebuked Darth Ravage when the latter agreed to Baras' request that the Council kill his former student. Declaring the Wrath's challenge valid and supported by Vowrawn, a member of the Council, Marr pitted Baras and his student against each other: the victor would be recognized by the Council as a true servant of the Emperor. As Marr and the other Councilors observed from their seats, the Wrath battled the false Voice in a duel within the Council chamber. As Baras faltered, he appealed to Darth Marr to defend the Emperor's Voice, but Marr refused. Ravage also refused when Baras ordered him to attack. A defiant Baras was forced to confront the Wrath to prove his power before the Dark Council until his former student defeated him. Marr then led the rest of the Dark Council in acknowledging the Wrath's position and right to free reign, but hinted that the Council would not tolerate actions that contradicted their own plans.
After Baras' body was removed from the chamber, Darth Thanaton—newly ascended to the Council after the suspicious death of his predecessor Darth Arctis—addressed his fellow Dark Lords. He appealed to the other Dark Councilors to aid him in destroying his rival and subordinate Lord Kallig, upon whom Thanaton had recently declared a Kaggath. The Kaggath, an ancient Sith ritual duel, had concluded on Corellia when Thanaton had fled to Korriban to meet with the Council. Thanaton was angered to see that Kallig had followed him to Korriban when the young Sith Inquisitor entered the chamber. Darth Mortis and Ravage mocked Thanaton's reliance on ancient tradition, and Marr cut short the Councilor's speech by addressing the matter at hand: why was Thanaton, a Dark Councilor, unable to defeat a single Sith Lord? Enraged, Thanaton began to duel Kallig, and their battle ended when the young Sith forced Thanaton to his knees in submission.

As the drained Dark Councilor struggled to rise, Marr rose from his seat to join Ravage, Vowrawn, and Mortis in front of their fallen colleague. They watched as Mortis broke Thanaton's neck to end his suffering. When Ravage expressed his disdain for Thanaton, Marr reprimanded him, stating that Thanaton had been a better Sith than Ravage gave him credit for. The Councilors then offered Kallig Thanaton's vacant seat. Ravage protested, arguing that a mere Lord could not be placed on the Council, but Marr silenced him, stating that Kallig had earned the right. Marr named the young Inquisitor "Darth Nox" and bestowed upon the new Dark Councilor the Sphere of Ancient Knowledge.
Following the deaths of Decimus, Hadra, and Acharon, and the Republic victory at Corellia, Marr ordered General Hesker and all Imperial forces to retreat from the planet and redirect to the new battlefield of Ilum. Mortis, Ravage, and Marr also dispatched Grand Moff Ilyan Regus to Ilum. Around this time, the Dark Council convened to discuss the successor to Hadra's seat on the council. Marr, fully aware of the Empire's deteriorating situation, nominated Darth Karrid and urged the other Councilors to support her, as the Empire's soldiers and resources were dwindling. To his dismay, the other Councilors present supported Darth Gravus, primarily due to the Empire's discrimination against non-humans. When Karrid killed Gravus, Marr was surprised by the Council's sudden shift in support for Karrid, but also concluded that these recent actions were simply another example of Sith infighting.

In 3638 BBY, Marr learned of the Hutt Cartel's activities on Makeb and contacted the Empire's heroes to address the threat. Meeting with each of them individually, he explained that he had chosen them because he was preoccupied with the rest of the war, as the Emperor remained absent. With the Republic nearing victory, the Hutts had seized Makeb to mine isotope-5, a substance capable of manipulating gravitational and electromagnetic fields, making it a powerful energy source that the Empire desperately needed for its defenses. Marr assigned a limited support team to assist the heroes, but cautioned them to proceed with stealth to avoid revealing their intentions to the Hutts and the Republic.
Unfortunately, Marr was later dismayed to learn that the Hutts had used all the available isotope-5 to create war droids and that their excessive mining of Makeb's core threatened to destroy the planet and the isotope along with it. After emphasizing that three Imperial worlds had fallen to buy the Makeb team time, the latter managed to stabilize the planet's core and keep it secret from their enemies. Upon learning of the success of the Empire's efforts, Marr refocused his attention on the galactic war.
Soon after, the Empire located the defected Dread Masters' base of operations on Oricon. Knowing that the plans of the now-rogue Masters boded ill for the entire galaxy, Marr contacted the Empire's heroes once more and instructed them to find Lord Hargrev, who was supposed to have responded to Imperial comms. He told the heroes that the Dread Masters had to be stopped, or all would be lost.

The actions of the Nova Blades pirates working for the Order of Revan altered the hyperspace routes, drawing Darth Marr's fleet to Rishi at the same time as the Republic forces under Satele Shan. The two fleets engaged each other but were interrupted when an associate of Lana Beniko revealed that the battle had been orchestrated by Revanite traitors aboard both fleets. Upon learning that Revan was still alive, Marr agreed to a temporary truce with the Republic forces under the command of the Grand Master and met with Satele Shan in the town of Raider's Cove on Rishi's surface. Marr revealed to both the Republic and Imperial forces that he had become aware of the Emperor's plan to extinguish all life in the galaxy and that he had no desire to serve as a pawn in the Emperor's madness. Marr explained that if Revan were to revive the Emperor as he planned to, no one would be able to stop him from carrying out his plan to eradicate all life in the galaxy and that Revan had to be stopped from bringing the Emperor back from his incorporeal form. The combined fleets joined forces and traveled to Yavin 4 where they established a coalition in order to stop Revan.

After establishing a base camp on Yavin 4's surface, it became clear that the Republic and Imperial rank and file still distrusted each other and needed to be convinced to stand against Revan together. Both Marr and Shan sensed a strong presence in the Force on the moon, which was neither the reborn Revan nor the Emperor. After the two sides established sensors enabling them to scout the area near the Temple of Sacrifice, they picked up a signal that Marr recognized as belonging to the Imperial Guard training facility. Marr and Beniko detained Commandant Iven amidst the Revanites who had ransacked the facility, after which Marr questioned him to learn more about the Emperor and Revan's plans for him. The combined forces of the Republic and the Empire cleared the path to the Temple of Sacrifice, after which the most powerful members of the Coalition went to confront Revan directly.

In the final battle against Revan, Marr fought alongside Satele and Theron Shan, Lana Beniko, Shae Vizla and the Wookiee Jakarro for the future of all life in the galaxy. After a difficult fight and despite being temporarily overpowered by Revan throughout the fight, the group managed to defeat him. Despite their efforts, the Emperor returned to life, feeding on the deaths the Coalition caused among the Revanites, which greatly puzzled Marr, as the Emperor did not take a physical form or possess a body and left Yavin 4 as soon as he appeared. Revan reunited with his dark half and finally became one with the Force. In the aftermath of the fight, Marr appointed Lana Beniko as the leader of the new Sith Intelligence. Darth Marr then rechristened the Emperor's Wrath as the new Wrath of the Empire and placed Darth Nox among the Elite of the Dark Council then proceeded to tell them that they were the only Sith Lords he could trust.

Following the events on Ziost, Darth Marr led a joint Republic and Imperial fleet into Wild Space in search of both Vitiate and the unidentified invaders who had raided several planets belonging to the two major galactic powers before retreating into unknown space. The fleet consisted of seven vessels, including Marr's own destroyer as flagship. Marr sensed that he was nearing Vitiate and knew that if he found him, he would persuade the Dark Council to send more forces, although he doubted the Republic would offer further assistance, despite their helpful contributions thus far. Suddenly, the Eternal Fleet appeared before the Republic and Imperial forces and engaged them, launching several boarding pods into the flagship. Skytroopers, the enemy boarders, caused chaos throughout the ship as Darth Marr helped to defend the bridge. Despite his efforts to prevent the ship's loss, he eventually concluded that there was nothing more he or his companion, the Commander, could do and asked the latter for their next course of action.

Following the catastrophic loss of his vessel and the ensuing combat, Marr, along with the Outlander, were taken as prisoners aboard the flagship of Prince Arcann, the Eternal Flagship, and transported to Zakuul, the capital city of the Eternal Empire. Once there, the prince escorted them to his father, Emperor Valkorion, the ruler of the Empire, whom Darth Marr swiftly recognized as yet another guise of Vitiate. Marr and the Outlander disclosed their mission to eliminate Valkorion, but the Emperor instead proposed that they align with him. Darth Marr unequivocally rejected Valkorion's proposition and launched an assault, slaying several of the Emperor's royal guards. Before Darth Marr could advance any further, he was struck directly by a blast of concentrated Force lightning from Valkorion, resulting in the Sith Lord's demise.

Despite the death of his physical form, Marr, unwilling to abandon the Sith Empire without defense, transitioned into a Force ghost. After a span of five years, his spectral form connected with Satele Shan, both sensing the presence of Valkorion. Subsequently, they journeyed together to Odessen, which served as the central base for the Outlander's Alliance, a coalition of individuals from both the Empire and the Republic, unified in their opposition to the Eternal Empire. While Satele commended their dedication, Marr expressed his sorrow that many would perish in the approaching war.
Later, Marr and Satele encountered the Outlander, who had fallen unconscious after absorbing a portion of Valkorion's power. They engaged in a debate regarding whether to spare or eliminate the Outlander, ultimately opting for the former, recognizing that the Outlander embodied the last flicker of hope for the galaxy. Marr remained unseen as Satele interacted with the Outlander, eventually revealing himself as Satele explained the viewpoints of Arcann and the Knights of Zakuul concerning the Force. Marr informed the Outlander that to triumph over Arcann, they needed to acquire fresh perspectives and arm themselves with new weaponry. As the Outlander gathered various items throughout the valley, Marr advised that defeating Arcann alone was insufficient, asserting that the Outlander was destined to claim the Eternal Throne to restore order to the galaxy, warning that any alternative path would result in chaos.

Following an encounter with a vision of Vaylin within a dark cave, Marr cautioned that it served as a warning from the Force, indicating that Arcann and Vaylin commanded an army prepared to confront any who dared to oppose them. He then instructed the Outlander that their previous weapon was designed for a different conflict and era, and they would need to construct a new weapon capable of uniting the galaxy and ultimately defeating Arcann. Once the weapon was completed, Marr predicted that the Outlander would emerge victorious in their next confrontation with Arcann, but cautioned that leading the Alliance was a vastly different undertaking than their previous role.
After the Outlander completed their final trial at the jurgoran's oasis, Marr conveyed to the Outlander that the Alliance would crumble if the Outlander lacked a clear understanding of their own identity and the ideals they championed. Having imparted all that they could, Marr and Satele sensed a calling within the Force, signaling that their exile on Odessen had come to an end, and they departed.

In 3626 BBY, Marr made another appearance to the Outlander within Satele's mind, as they attempted to thwart Tenebrae's resurrection. Marr clarified that Satele possessed far greater strength than the Sith Emperor had believed, and that she was not the vulnerable target he perceived her to be. He elaborated that, while the Emperor grew in power by drawing upon the memories and impressions of his former self from Satele and her followers, he lacked the wisdom gained through experiencing them. Thus, despite remaining the most formidable being in the galaxy, Tenebrae was more susceptible than he wished his adversaries to believe. Marr proposed that the ritual etched onto Tenebrae's original body must have been created centuries prior, potentially even before Revan's era. As the Outlander prepared to confront Tenebrae, Marr materialized alongside all those who had been victimized by Tenebrae throughout the ages, joining the collective effort to permanently eliminate the Sith Emperor, declaring that the Sith would surpass him and that all his power would fail to save him. With Tenebrae finally defeated, Marr became one with the Force.

Darth Marr, a male human, gained notoriety for consistently concealing his true identity. The Dark Lord remained perpetually clad in his custom-designed suit of battle armor, and it was rumored that the sight of Marr's actual face had driven Moff Xerxian to commit suicide. Marr opted to maintain this appearance as a Force Ghost, desiring to be remembered as a symbol. Throughout his tenure on the Dark Council, Darth Marr's physical form underwent a gradual transformation due to his deep immersion in the dark side of the Force. By the time war erupted once more with the Republic, the Sith Lord recognized that his body was nearing its end. Marr was fueled by an intense commitment to warfare, bordering on fanaticism. He firmly believed that conflict was the sole means through which life evolved and grew stronger, and he personally viewed death as an inevitable occurrence, with only cowards attempting to evade what was ultimately necessary. Over the decades, Darth Marr's command of the dark side progressively eroded his emotions, leaving him with only a fraction of his original humanity but a profound desire to ensure the Empire's survival.

The Sith Lord understood that the Empire was in need of evolution to ensure its continued existence. He grew increasingly frustrated by the bigotry exhibited by his fellow Councilors and their adherence to outdated anti-alien ideologies, even after the Empire began integrating alien species into its ranks following the defeat of the traitorous Darth Malgus at the Battle of Ilum. Furthermore, Marr differed from the majority of Sith, who held the Jedi in contempt. Instead, he held them in high regard as warriors and Force wielders, even considering Jedi Grand Master Satele Shan as the sole individual in the galaxy worthy of being his equal. Marr was also aware that the ongoing acts of betrayal and internal conflict would lead to the Empire's demise, and he endeavored to maintain control during the Emperor's absence. Marr expressed disappointment when Karrid chose to eliminate Gravus for her own selfish motives, which secured her a position as a Dark Councilor but simultaneously weakened the Empire.
Marr developed considerable respect for Darth Thanaton, informing Ravage that Thanaton was a superior Sith than Ravage acknowledged, and also conveying to Darth Nox his surprise at witnessing Thanaton's downfall.
In the aftermath of his death, Marr conceded that his unwavering resolve had rendered him inflexible and developed a revised understanding of the Force, acknowledging the truth inherent in the final mantra of the Jedi code, "There is no death, there is only the Force", and its underlying purpose.

Darth Marr, a Sith Warrior, was an extraordinarily potent practitioner of the dark side; his strength was such that he earned a position on the Dark Council while still in his early twenties. He maintained his position for the next four decades, while some Councilors' tenures lasted only weeks. Even Emperor Vitiate recognized the potential threat that Darth Marr, along with Darth Mortis, posed to his throne. He wielded a single red-bladed lightsaber in combat, protected by his specialized suit of Sith battle armor, and his combat prowess was such that he was renowned for routing entire armies, with some claiming that the Dark Council member was more effective than a Planetary Defense Shield. During a sparring session with Darth Lachris, Marr displayed sufficient speed to seemingly "teleport" in Darth Lachris' perception. Darth Marr also possessed proficiency in the use of Force lightning, capable of summoning a crackling storm of lightning instantaneously to intimidate the impudent Teneb Kel.
Darth Marr made his initial appearance in The Old Republic, Blood of the Empire Act 1: Shades of the Sith, the fourth installment of the Star Wars: The Old Republic comic series and the first within the Blood of the Empire arc. He reappears in Act 3: Burn the Future, and is featured in numerous flashbacks throughout the early issues of The Lost Suns story arc—most notably on the cover of The Lost Suns, Part 2.
Darth Marr is a character in the finales of both the Sith Warrior and Sith Inquisitor storylines in Star Wars: The Old Republic, the massively multiplayer online role-playing game developed by BioWare and LucasArts and released on December 20, 2011. In the Sith Warrior finale, "Retribution", Marr occupies the throne third from the left on the left-hand side of the chamber. However, in the Sith Inquisitor finale "The Dark Council", Marr is instead seated on the far right throne on the left-hand side.
In content released after the main class storylines for The Old Republic, Darth Marr becomes a significant NPC, assuming a leadership role within the Empire and acting as the direct superior and quest-giver for Imperial players (a role fulfilled by Satele Shan and Leontyne Saresh for the Republic).
Michael Harney provides the voice for Darth Marr.