Hyperion is a superhuman being of unknown origin, who lives on the Earth of his alternate dimension, which is sometimes designated as "Other-Earth" or "Earth-S." He found and adopted by a kindly couple, the Miltons, who instilled in Hyperion, whom they named Mark, a strong love of traditional American values and a passion for justice. Mark proved to have vast superhuman powers, which the Miltons encouraged him to use for the good of humanity. However, they cautioned him not to use his powers to change the course of human history, for they believed that humanity must ultimately solve its own problems.

As in adult Mark Milton worked as a newspaper cartoonist in the city of Cosmopolis. He assumed the costumed and masked identity of Hyperion (taking the name from the Titan in Greek mythology who was associated with the sun) in order to use his superhuman powers to fight crime and to help save lives. Hyperion's greatest enemy was the criminal scientist Emil Burbank, who assumed the costumed persona of Master Menace.

Hyperion became a founding member of the Squadron Supreme, an organization of costumed champions; most of who possessed superhuman powers. His best friend in the team was Nighthawk, who was actually multi-millionaire Kyle Richmond. Acclaimed as the greatest hero of his world, Hyperion acted as leader of the Squadron.

The Grandmaster, an alien from the dimension of "mainstream" Earth, journeyed to the Squadron's dimension and set up a competition between himself and the Squadron's enemy, the Scarlet Centurion. The Grandmaster used the Squadron members as pawns in a tournament to compete against the Institute of Evil, a team of the Squadron's foes organized by the Centurion. Winning the contest, the Grandmaster resolved to create his own Squadron the next time he needed superhuman pawns. Hence, he created a duplicate Hyperion from pseudo organic matter and used him in battle against the Avengers, a team of costumed champions based on "mainstream" Earth. This Hyperion became a criminal, usually acting as a member of the team called the Squadron Sinister.

A number of the Avengers later traveled to the Earth of the Squadron Supreme and aided the Squadron against a menace called the Brain-Child. Some time later, the government of the United States of "Other-Earth" came under the control of the Serpent Cartel, an organization of human agents of the extradimensional serpent-demon Set who controlled them through the power-object called the Serpent Crown. The Serpent Cartel even succeeded in placing the President of the United States of "Other Earth" under Set's control. The President dispatched several members of the Squadron Supreme, who were unaware of the Commander-in-Chief's new loyalties, to "mainstream" Earth to battle the Avengers, who were opposing Set's human agents there. A number of Avengers journeyed to "Other-Earth," where they managed to seize that world's counterpart to the Serpent Crown and to convince the Squadron they were being misled by their President. The Squadron, led by Hyperion forced the President's resignation and saw to the dismantling of the Serpent Cartel. Kyle Richmond was elected President in the next election.