Gladiator's history before he joined the Imperial Guard is largely unknown. He was born centuries ago, though the time period remains unspecified. He is said to descend from a proud bloodline, though the names of his ancestors remain unknown. He was raised by the Strontian council of elders. They were as much family to him as his blood relatives.
His earliest known memory also dates to centuries before. Kallark was a cadet on his native planet of Strontia, training with other young Strontian men and women. All cadets dressed in nearly identical uniforms. The uniform colors were red and blue, with yellow chest symbols. Each cadet seemed to have a different symbol, though the significance of this was left unexplained. They were competing for the title of Gladiator.
In an exercise, the cadets were flying and evading attacking strontium missiles. Kallark noticed his fellow cadet Tennet hit and falling from the sky. He chose to go rescue the falling comrade. He caught the young man. A nearby Strontian Elder chastised Kallark for abandoning his target and shirking his duty. Kallark left Tennet with the Elder and replied to the accusations. He felt that honor demands for a warrior to aid his comrade, provided this does not compromise the mission. He then flew away and attacked his target, a flying ship.
The pilot of the ship attacked Kallark with sorcery. This was not expected since the magical arts were forbidden on Strontia. Kallark was not afraid of the unexpected attach. He destroyed the ship, took the pilot prisoner, and delivered him to the Elder. The Elder commended him for a job well done. He then informed the cadet that he had won a spot on the final roster. He warned Kallark that the most difficult challenges were yet to come.
Later, Kallark stood with nine other cadets before the Strontian council of elders. These ten were the only ones to have completed the training mission. An Elder informed them about the purpose of their trials. The new Imperial Guard of the Shi'ar Empire would be a company of elites, and each race of the Empire may be represented by its finest warrior. The one chosen to be the Strontian representative will undergo an enhancement process to become Gladiator. His powers would be unmatched throughout the universe. The Elder warned the cadets that the enhancement process was life-threatening and few could survive it. He added that even fewer possess the strength of character to be trusted with its gifts.
The Elder informed the cadets that they are not going to choose among them. The choice would be made by Majestor T'Korr. Kallark and the other cadets soon met on the Majestor and knelt before him. He found them to be too young to be warriors, but Chancellor Vitana informed him that only the young could survive the Gladiator process. But reminded the Majestor that even an ordinary Strontian had the power to decimate an army. Hearing this, T'Korr had doubts about the loyalty of such a powerful subject people. He perceived that they could threaten the throne. He decided to test their loyalty.
T'Korr adressed Kallark and the other cadets, informing that he will make his selection among them. But only after they completed a mission for him. He stated that there was a group of potential threats that he needed them to face. They were wise and powerful. and they may plot against his rule. This group was their own Council of Elders and their mission was to slay them.
An unnamed female cadet was the first to react at the order. She called T'Korr mad and informed him that the cadets were loyal to the Elders. She attacked him and threatened to kill him. He killed her instead, leaving only 9 Strontian cadets. T'Korr reminded them that the Strontians have sworn undying loyalty to the Shi'ar Throne. So they should obey any order given to them. He ordered them to complete the mission or be killed like her. Kallark was the only one to reply, to proclaim that they would obey. He led the charge of the cadets.
As they attacked the Citadel of the Elders, cadet Harrald voiced his doubts to Kallark. He reminded him that the Elders were like family to them all. Kallark replied that the Elders raised them to be honorable and obey the orders of the Majestor. And this was exactly what they were doing. The other cadets were feeling doubt and their powers left them. Several were killed in the battle. Kallark mused that maybe it was for the best if all of them were killed, before having to choose their loyalty to the Majestor and their own home.
Changing his mind, Kallark proclaimed his own musing were but the mewlings (whimpers) of a coward. He decided his own feelings were irrelevant, only the orders mattered. He charged forward and broke through the Citadel, despite Harrald’s protests. The Elders were defended by several guards. Kallark fought them, but called for them to stand aside. His orders did not include harming them. He was here only to kill the Elders.
Harrald decided to change sides and defend the elders. He attacked Kallark and threatened to kill his friend. Kallark pointed that Harrald's voice betrayed his uncertainty, his own doubts preventing him from killing Kallark. Kallark stated that he had no uncertainty of his own. He smashed Harrald into a nearby wall and then used eyeblasts to kill the elders. He then exited the building.
A dying Elder informs Harrald that Kallark had just saved the planet. The Elders had bargained with the Majestor. A Shi'ar Starcracker was orbiting Strontia's sun. Had the cadets defied the Majestor's orders, he would have activated the Starcracker and cause the sun to go nova. Annihilating Strontia and all its inhabitants. If they obeyed instead, Strontia would survive. The Elders had chosen to secretly inform their most promising cadet, Kallark. They trusted him to do the right thing. The other cadets would have considered rebellion, secession, and war.
The Elder died with the certainty that Kallark would go on to serve the Imperium with honor and dedication. He would obey. Meanwhile, Kallark returned to the Majestor. He announced he was the only survivor, lying about the survival of Harrald. T'Korr realized that the cadet was aware of the true purpose of his mission. The Majestor explains to the Strontian that he is not a cruel man. The safety of countless worlds of the Empire depends on its Majestor. There was no room for doubt in either a ruler or the people that the ruler has to rely on.
T'Korr proclaimes that Kallark has proven himself. He named his Praetor (leader) of the new Imperial Guard. He also names him Gladiator. Regardless of the Majestor or Majestrix in charge, Gladiator would heed their orders
According to the family history known by Korvus, the Imperial Guard was formed to stop his ancestor Rook'shir. He was a Shi'ar outlaw who became an avatar of the Phoenix Force. Gladiator led the Guard against him to prevent him from destroying the Shi'ar Empire. Known members of the Guard at the time included Magique, Mentor, and Neutron.
The details of the battle between the Guard and Rook'shir have not been detailed. But the battle ended with Gladiator having defeated the Phoenix avatar. He was holding Rook-shir up by the head. He positioned the defeated foe in a kneeling position and prepared to deliver the killing blow. He used his right fist to decapitate Rook'shir. A piece of the Phoenix Force remained within Rook'shir's sword which became known as the Blade of the Phoenix. The Guard retrieved the sword following the battle.
Gladiator continued to serve succeeding rulers of the Shi'ar Empire, including Emperor D'Ken Neramani. Members of the Imperial Guard under his command at that time included Astra, Electron, Fang, Hobgoblin, Impulse, Magique, Mentor, Neutron, Nightside, Oracle, Scintilla, Smasher, Starbolt, Tempest, and Titan.
The X-Men (Banshee, Colossus, Cyclops, Nightcrawler, Phoenix, Storm, and Wolverine) teleported from Earth to the "World". There they found D'Ken, Eric the Red, the captive Lilandra and the gathered Imperial Guard. Astra asked Gladiator who were these people, and whether the new arrivals were friends or foes.
Realizing that they can understand each other's language, the two teams started to talk. Representing the X-Men, Cyclops explained that they came to get Lilandra and Eric the Red. Gladiator introduced himself and his team. He also pointed that the X-Men were surrounded and outnumbered. He next explained that Lilandra was both a princess and a traitor to the Empire. He declared that the Guard would not surrender the prisoner. In reply, Cyclops attacked Mentor and started a battle between the two teams. Gladiator swore that Cyclops would pay for his attack, and that he would personally kill him the mutant with his bare hands. He next commanded the Guard to attack.
Nigtcrawler teleported Lilandra out of danger. She explained to Cyclops her own background, the civil war of the Shi'ar, and how it affected their own recent battles on Earth. She pointed that D'Ken seeks absolute power. Overhearing her explanation, Gladiator approached the princess. He asked Lilandra what right she had to deny this power to her emperor. Reminding Lilandra that she herself swore an oath of service to D'Ken. She replied that that oath was sworn to a madman, asking Gladiator to open his eyes. Or else D'Ken's dreams of imperial glory would close these eyes forever.
Gladiator answered that he did not care of the consequences. The Guard's role is not to question orders but obey them. Adding that By D'Ken's will, Lilandra and her companions had to die. Gladiator managed to grab Lilandra and added that he would not listen to her. He regretted ever caring for her. Lilandra was still trying to reason with him. Claiming that she was only seeking to save the Empire while D'Ken is fated to destroy it. Gladiator asked her how she knows what D'Ken was going to do. She admitted that she does not know but only fears. But that the power D'Ken seeks was known as "the End of All That Is".
The conversation between Gladiator and Lilandra ended at this point. Gladiator was attacked by a laser beam by the arriving Starjammers. He was seemingly knocked out. The combined forces of the X-Men and the Starjammers finished off the rest of the Guard, winning the battle. The unconscious body of Gladiator was seem on the ground at the battle's ending.
D'Ken pointed that their victory was only temporary. He called for his foes to look to the sky above them. At this point a gateway opened, blue-white light emerged and poured into the nearby M'Kraan Crystal. For a fraction of a second all reality ceased to exist. Gladiator and the Guard remained unconscious while Jahf emeged to face the X-Men and Starjammers. When Jahf fell, Modt emerged to replace him. During the fight D'Ken was thrown in the Crystal. He and everyone conscious nearby were transported to the interior of the Crystal. Phoenix had to fight her own battle in there.
The X-Men emerged triumphant from the Crystal back to the "World". By this point Gladiator, Nightside, and Starbolt had regained consciousness and were ready to attack them. They intended to follow D'Ken's commands and kill them. Lilandra spoke directly to Gladiator and prevented him from attacking. She claimed that with D'Ken out of the way, the throne belonged to her. The Guard had to obey her.
At this point, Araki arrived and explained that Lilandra was not empress yet. D'Ken was now mad and the throne vacant, but she legally remained a traitor. It would take time to clear her name and summon her to be crowned. Afterward the X-Men and Lilandra were teleported to Earth. Lilandra explained that D'Ken was driven insane and catatonic by the experience. For the time being the Shi'ar throne was vacant and she stood as the main candidate for it. But until the High council decided to summon her to receive the throne, she would spend her exile on Earth. This would mean that Gladiator and the Guard were no longer their enemies.
In time Phoenix turned to Dark Phoenix, a major threat. In the Imperial Center, ruling seat of the Shi’ar Empire, Empress Lilandra and her ministers of the Grand Council observe a viewing screen. They see the Dark Phoenix approach Earth. Gladiator stood in guard at the Center. Lilandra started speaking, comparing the threat posed by the Dark Phoenix to Galactus. Yet she argued, the new threat was greater than the old one. Both beings felt infernal hunger and the need to consume. But Galactus consumed only individual worlds, while the Dark Phoenix could consume everything in existence. Lilandra decided that the Dark Phoenix had to be destroyed for the universe to survive.
The X-Men (Angel, Beast, Colossus, Cyclops, Nightcrawler, Phoenix, Professor X, Storm, and Wolverine were teleported aboard the flagship of the Shi'ar grand fleet. Gladiator spoke to them, reminding them of his codename and status as Praetor. He announced that they were in the presence of Empress Lilandra and their fate rested in her hands.
Lilandra announced her decision that the Phoenix had to be destroyed for the universe to remain safe. She continued that since "Jean" could not cope with her near-infinite abilities, the Shi'ar can no longer do nothing about the threat she posed. She asked Gladiator to continue in announcing her plans. Gladiator explained that Dark Phoenix was a chaos-bringer and a ravager of worlds. Responsible for the deaths of 5 billion inhabitants of the D'Bari star system and the destruction of a Shi'ar warship. The X-Men react in shock that one of their members is a mass murderer.
Lilandra asked the X-Men to surrender "Jean" to Shi'ar custody. Cyclops then claimed that Dark Phoenix no longer existed. "Jean" no longer has access to that power. Lilandra argued that "Jean"'s depowerment could be only temporary. She also argued that as long as Phoenix existed in any form, at any power level, she would be a deadly threat to all that lives. The risk is too great to let "Jean" survive. She ordered her warriors to capture "Jean", Professor X then shouted the ceremonial words “Arin’nn Haelar", challenging Lilandra to a duel of honor for the life of "Jean Grey".
Lilandra decided that she had to stop proceedings and consult her allies before making a decision. Said allies were the Supreme Intelligence, ruler of the Kree Empire and Empress R'Kill of the Skrull Empire. They both agreed to the duel, provided that their representatives would monitor the battle. Lilandra decided that the duel would begin at dawn.
The following day, the flagship transported the combatants to the Moon. The Imperial Guard would represent Lilandra on the battlefield. Lilandra announced the terms of the battle. The two teams would fight until only one remained. If the X-Men won, their survivors would be set free. If the Guard won, Phoenix would belong to the Shi'ar. The chosen battle ground was the Blue Area of the Moon.
Professor X was excluded from the combatants, leaving only 8 X-Men on the battlefield. The X-Men split into two groups, each with four members. A group consisting of Beast, Colossus, Storm, and Wolverine encountered and fought Warstar. While Colossus fought C'cil and Beast fought B'nee, Storm and Wolverine stayed on the sidelines. Gladiator approached the two X-Men from behind and ripped up the floor that they were standing on. Storm and Wolverine consequently fell into a pit.
While Warstar continued to face his opponents, Gladiator observed the battle. He eventually realized that Warstar was loosing the battle. Colossus knocked out C'cil and B'nee knocked out the Beast. Leaving the two of them to face each other, with Colossus outclassing his opponent. At this point, Gladiator intervened and attacked Colossus. He explained that for Colossus to get to any other members of the Guard, he would have to go through him first. And he self-confidently announced that victory was impossible for Colossus. Gladiator knocked Colossus into a wall.
Colossus considered that Gladiator was as strong as himself. But decided that perhaps he was more vulnerable to harm. Colossus dropped an entire pillar on Gladiator, who seemed completely unfazed. The opponents then engaged into a brutal fist fight. The ancient, fragile structures around them crumbled and collapsed on top of the two combatants. They were buried below mountains of rubble. After a while, Gladiator managed to lift boulders and emerge from the rubble. His uniform was torn but his body was unharmed. He was the victor by default. He took time to rescue the unconscious Colossus.
Cyclops and Phoenix were the last X-Men left standing, holding their own against Oracle, Smasher, and Starbolt. Gladiator flew to their position to join the battle. An energy flare from the moon served to announce that the Phoenix was back. Deciding that the Guard had no chance to win against the threat, Lilandra was prepared to destroy the Moon, the Sol, and the entire star cluster. All in hopes of killing Phoenix. Gladiator and the Guard were seen unconscious, defeated by the Phoenix. At the end, the Phoenix committed suicide, seemingly eliminating the threat.
He was one of the Guard members chosen to battle the X-Men over the fate of Jean Grey, who had seemingly become the Dark Phoenix.
Kallark was later charged with pursuing a group of Skrulls posing as a superhero team. He believed the Fantastic Four to be this group and attacked them. Captain America and Spider-Man found the real Skrull group and assisted in their capture.
Kallark was among a number of Imperial Guard members temporarily relocated to Earth. After learning of a Phalanx invasion of Shi'ar space he confronted Cannonball, sending him, the Beast, Trish Tilby, Joseph and Rogue to assist in his stead.
At another point, Kallark was enlisted by Pip the Troll to try and liberate the planet Skardon from the apathetic rule of the Champion of the Universe (because Skardon law would not recognize the legitimacy of any challenger unless they could beat the Champion in a boxing match). Kallark fought against the Champion, but lost because the Champion possessed the Power Gem which allows it's wearer access to all the power that has or will exist. Kallark spent a period of time recuperating from his injuries; meanwhile, She-Hulk convinced the Champion to remove the Power Gem, and subsequently pummeled him into submission.
Kallark was sent to Earth to find the Uni-Power, which was traveling from host to host for help against Krosakis. He found it with the Invisible Woman, and was able to convince it to come with him. Krosakis attacked Kallark and the Uni-Power as they left Earth. The Silver Surfer intervened and returned the Uni-Power to Earth while Kallark took Krosakis into Shi'ar custody.
Fighting and serving Vulcan
When Vulcan captured a Shi'ar cruiser with intention of attacking the Shi'ar Empire the Imperial Guard were dispatched to stop him. Vulcan was able to hold is own against the gathered forces but was finally defeated by Kallark (who seriously injured Vulcan).
Vulcan later married Cal'syee Neramani (Deathbird) and upon murdering then Shi'ar Emperor D'Ken ascended to the throne as Emperor Vulcan. Kallark conferred with his new Empress before following the orders of Vulcan, but did so nevertheless.
War of Kings
Gladiator served his new Emperor as he had all others in the past but eventually disobeyed his orders (in this case, the execution of Lilandra) and rose up against his Emperor.
He was present when Lilandra was assassinated by the Fraternity of Raptors agent known as Razor. Razor had taken over his host Chris Powell (Darkhawk) but was overridden too late to stop the assassination.
With Vulcan presumed dead and Deathbird incapacitated, Gladiator took leadership of the fragmented Sh'iar empire in order to prevent another civil war. The Shi'ar, having lost the war with the Kree however fell under their rule.
After the Phoenix arrived on Earth and chose five hosts from among the X-Men, Kallark traveled to Earth in order to stop them and rescue his son. He was no match for the Phoenixes however and was defeated and beaten down. The Phoenixes spared him, and Kallark and his son left Earth.
Prelude to Infinity
Kallark arrived at the border of the Shi'ar Empire following the inertial alert from Operation: Broken Frontier. After the death of Superguardian Smasher (Galin) during the action, Gladiator promoted Izzy Kane to be the Superguardian for the Shi'ar Imperial Guard, noting that she was the first Guardsman from Earth. During the interrogation of a member of the race that invaded the empire, the Majestor learned that they had only attacked the empire because they had been fleeing a greater threat.
This threat that forced the aliens to attacked the Shi'ar Imperium revealed itself to be known as the Builders. Kallark joined the Galactic Council alongside with the Avengers to eliminate the Builders. Following the defeat of the Builders, Gladiator planned to expand the Imperial Guard.
When the focus of the decay of the universe was found to be the Earth, the Majestor addressed the Galactic Council, and decided that the Earth had to be destroyed to save the universe. Even though they planned a sneak attack on the Earth, the Guardians of the Galaxy managed to discover the Shi'ar's plan and warned the Avengers.
While approaching Earth, the Shi'ar alerted humanity that they had two hours left to live until Earth was destroyed by their fleet. Using a super weapon capable of channeling the Earth's power, Sunspot and A.I.M. retaliated against the Shi'ar in front, while S.H.I.E.L.D.'s Avengers used a Planetkiller seized from the Builders to attack from behind. However, A.I.M.'s weapon overheated and exploded, and the Planetkiller was destroyed by the Annihilation Wave. With no options left, the Avengers prepared to meet their end. However, the Illuminati used the controller disk of a rogue planet that shared the same space with Earth while phased while Iron Man flew to the Sol's Hammer, and prepared to use it.
Iron Man charged and fired Sol's Hammer, successfully destroying the Shi'ar fleet, including the Majestor.