The super-being that would become known as Hyperion is a native of Earth-712, who was the last surviving member of a race of Eternals. Although the circumstances are unknown, Hyperion was adopted by the Milton family who raised him as their adopted son Mark Milton. Mark was raised with a strong moral code and eventually became the super-hero named Hyperion, after the Greek Titan. As an adult he moved to the city of Cosmopolis, New Troy and took up a job as a cartoonist for a news publication as well as starting a relationship with fellow reporter Lonni Lattimer.
During his early career as a hero, Hyperion clashed with villains such as Emil Burbank, and also formed a lasting friendship with fellow costumed hero Nighthawk and joined him and others in forming the Squadron Supreme, a league of heroes that fought for justice on their Earth. In his adventures with the Squadron, Hyperion clashed with such foes as the Institute of Evil and the Scarlet Centurion. During one such battle Hyperion and the other members of the Squadron were manipulated as pawns in a Contest of Champions between the Centurion and Earth-616's Grandmaster, where they were pitted against the Institute of Evil. The Squadron won this battle — however, it would inspire the Grandmaster to create his own Earth-616 version of the group called the Squadron Sinister, including an artificial construct of Hyperion.
This would not be Hyperion's last encounter with beings from Earth-616: shortly thereafter he met the Avengers, heroes native to Earth-616 who were accidentally transported to Earth-712. With the Squadron, Hyperion worked together with the Avengers in stopping Brainchild from causing the destruction of the Earth.
Hyperion and the other Squadron members ended up in a series of exploits that had their wills subjugated by a higher power, usually forcing them to clash with heroes from Earth-616. In the first such attempt, the Squadron Supreme were put under the control of President Nelson Rockefeller who was then being manipulated by the Serpent Crown of Earth-712. In a bid to take over the universe with his Serpent Cartel Rockefeller worked with Earth-616's Hugh Jones C.E.O. of the Roxxon Oil Company. This led to Hyperion and the Squadron Supreme clashing once more with the Avengers. The Avengers however freed the Squadron from the Serpent Crown's influence, and crushed the Cartel's influence over the government of Earth-712, leaving it in the Squadron's hands while they disposed of both Serpent Crowns on Earth-616.
When movie producers on Earth-712 began making a film based on the adventures of the Squadron Supreme, Hyperion traveled to Earth-616 to ask the Avengers to participate in the film. Hyperion only found Thor and the two ended up in a plot orchestrated by Emil Burbank and the evil Hyperion of Earth-616 to get the two to clash with one another. When the truth was learned, Hyperion and Thor defeated both foes together.
Hyperion and the Squadron were once more manipulated by the Overmind and Null the Living Darkness. This came at a time when Nighthawk, in his identity of Kyle Richmond was President of the United States. Overmind and Null took over the entire world and spun it into utter chaos, using the Squadron Supreme as their elite force. The Squadron and their world were freed from Overmind and Null's tyranny by the intervention of the Defenders from Earth-616.
With their world left in chaos, Hyperion decided that the Squadron needed to gain control of the entire world. Meeting with the other Squadron members, Hyperion suggested that the group take on the task of protecting the world on a larger scope. Inspired by fellow Squadron member Power Princess' people of Utopia Isle, Hyperion suggested that they tackle the real evils of the world: crime, poverty, hunger, and even death. They decided to begin what was dubbed the Utopia Project, in the belief that their work would turn Earth into a Utopia. Believing that interfering with peoples lives in such a way to be unethical, Nighthawk quit the group. During the night, Kyle Richmond stepped down as President of the United States, Hyperion and the Squadron all unmasked, revealing their true identities to the world as an act of good faith to get the people on their side and on the side of the Utopia Program. During this public announcement, Hyperion unknowingly came very close to being shot by Richmond with a bullet made out of Argonite, the one substance that is lethal to him, however Kyle could not bring himself to pull the trigger.
Hyperion aided the Squadron in restoring basic human commodities, breaking up looting and protecting the world from threats such as the Scarlet Centurion and the Institute of Evil. During this time, the Squadron also took away the world's firearms, replacing them with non-lethal weapons such as force-field devices and energy pistols that encased their targets in spheres. The Squadron also created cryogenic devices to keep the terminally ill frozen until such a time they could be restored to life and cured of their ailments. Most controversial of all was the B-Mod machine, a device that removed the criminal tendencies of those who were arrested. Although this device was only used on a voluntarily basis, a number of the Squadron members quit the group after its purpose was abused. As Hyperion aided the Squadron in B-Modding their enemies, the Institute of Evil and other villains, Nighthawk recruited a team of villains and Squadron defectors to try and stop Hyperion's Utopia Program.
Fearing that he would be subject to the B-Mod machine, Hyperion's old foe Emil Burbank - now calling himself Master Menace - pulled the evil Hyperion of Earth-616 from a dimension limbo and contrived a scheme to replace the Earth-712 Hyperion with his doppelganger. Trapping the real Hyperion in the same limbo dimension, Burbank's plot succeeded until the evil Hyperion fell in love with Power Princess and started a relationship with her after he secretly killed her elderly husband. The evil Hyperion then trapped Burbank in the limbo reality with the real Hyperion. The old foes worked together to free themselves, and in a battle to the death Hyperion ultimately killed his evil duplicate. The battle was not without a personal loss for Hyperion, as the overtaxing of his atomic vision caused his retinas to burn out, leaving him blind. However he was equipped with special glasses that allowed him to see for a time.
Later, Nighthawk and his Redeemers infiltrated the Squadron Supreme and then staged an attack on their compound in an attempt to dismantle the Utopia Program. The battle ended with many casualties, Nighthawk included, who managed to convince Hyperion of the errors in creating the Utopia Program, in that while their intentions were good eventually someone would abuse it for their own selfish ends. With his best friend dead, Hyperion surrendered the Squadron Supreme to the Redeemers and the Utopia Program was dismantled.
While the Squadron was trapped on Earth-616 after their battle with the Nth Man, the blind Hyperion met Quasar and Makkari. Makkari noted that Hyperion was of a similar race to the Eternals and instructed him on using his body's energy to heal his blindness.
After numerous adventures on Earth-616, the Squadron Supreme, working with the Avengers and their associates Swordsman and Magdalene, and the Project Pegasus staff utilized a recovered Nth Projector to return the Squadron to their home reality, where they discovered that their Earth was taken over by the Global Directorate. After several Squadroners were injured, the original members banded together with the son of the original Nighthawk and a returned Skrullian Skymaster to try and undo the damage done to their world in their absence.
In recent times, Hyperion was called to the Panoptichron, a crystal palace connected to the multiverse, by Beak, a mutant from Earth-616 who was then a member of the reality jumping Exiles, to help his teammates battle an evil Hyperion from Earth-4023 who intended to use the Panoptichron to take over the multiverse. With the aid of a Hyperion from Earth-5764 and the Exiles, Hyperion succeeded in sending his evil alternate universe counterpart back to his home reality. When both good Hyperions expressed their concern about leaving the Panoptichron in the care of the Exiles it was Beak who once more convinced them to leave.
This was not Hyperion's last encounter with the Exiles: When Proteus of Earth-58163 (then in the body of Hulk (John Eisenhart) of Earth-6375) arrived on Earth-712 fleeing the Exiles, he convinced Hyperion and the Squadron that the Exiles had been abusing their responsibility, and then fled to reality Earth-9200. Hyperion and the Squadron clashed with the Exiles before Proteus' trick was revealed. Not entirely sure that the Exiles were able to handle Proteus on their own, Hyperion sent Power Princess to join their ranks and put a stop to the mutant serial killer's reality jumping.
Most recently, Hyperion was among the members of the Squadron Supreme pulled to Earth-31916, home to an alternate reality version of the Squadron and got involved with their counterpart and a combined force of heroes from Earth-1610 to prevent the destruction of Earth-31916.
When Hyperion's reality started suffering an an ongoing cataclysm of unknown origin which threatened to destroy the Earth, Hyperion insisted for Zarda to use a portal to escape their homeworld's destruction, as there was only time for one person to enter it. Zarda, at first, protested against this action; however, Hyperion told her to go and remember their life and team as Zarda entered the portal, leaving him to die.