For countless millennia in the actuality of Earth-712 the Skrull Empire has been at war with the Kree Empire. In an attempt to end the bloodshed the Skrull Empire created a means to imbue their soldiers with extraordinary powers, "Super Skrulls", to vanquish the Kree. Skymax was the first soldier experimented on, and barely managed o make it out of the Skrull homeworld before the World Devourer destroyed it. The Skrull empire was destroyed and the survivors were scattered. Skymax attempted to find survivors but was unsuccessful. Skymax met misfortune in the vicinity of Earth when his starship malfunctioned. He was rescued and taken to Earth by American astronaut Joe Ledger. Grateful for his rescue, Skymax gave Ledger a Power Prism which Ledger used to become the costumed adventurer Doctor Spectrum, while Skymax became the costumed adventurer known as the Skrull. Skymax and Ledger both became founding members of the Squadron Supreme and Skymax remained with the team until member Tom Thumb repaired his ship allowing him to return to space. Skymax realized that the damage to his ship was beyond repair despite Tom Thumb's efforts and he chose to remain on Earth in secret, searching for any possibility of other Skrull survivors. Not finding any Skymax concluded that he was indeed the last of his race and he stayed on Earth.
After the Squadron returned from their adventures in Earth-616, the sorcerer Mysterium sent the surviving members to retrieve others to help in the rebellion against the Global Directorate. Doctor Spectrum was sent after "the Watcher" and discovered Skymax. Renaming himself the Skrullian Skymaster, and revealing his true origin to Doctor Spectrum, Skymax rejoined the Squadron Supreme and settled with them on Utopia Isle.
The dimension hopping Proteus appeared in the 712 dimension and convinced the Squadron to attack the Exiles who were following closely behind him. The Squadron defeated and captured the Exiles and placed them on trial. After the timely intervention of Heather Hudson, Skymax and the rest of the Squadron learned the entire history of the Exiles, as well as the true history of the Global Directorate. Deciding their reign had come to an end, the Squadron arrived at the Global Directorate's headquarters and ousted them from power.
Currently Skymax is helping the Squadron restore freedom to their world.