Journey into Mystery #83 (1962)
Ria in the Krona star system
Kronans are space-capable, utilizing an anti-gravity device called the gravitron for interstellar travel. They have also created robot, including the Mechano-Monster and Mekkanoid, and have constructed force fields, disintegration pistols ("astro-blasters") and devices that generate sophisticated illusions.
In recent times, the Kronans established an outpost on Lapetus, a moon of Saturn, earning them the nickname "Stone Men of Saturn". An invasion force which included brothers Korg and Margus landed in Norway, but their arrival was witnessed by Dr. Donald Blake (a human form which Thor had been placed in by his father Odin). Blake fled from the Kronans and discovered in a nearby cave the hammer Mjolnir, which caused him to rediscover his true identity as Thor. Thor overpowered the Kronans and their greatest weapons, and the Kronan fleet fled Earth, fearful that there could be others as powerful as Thor.
One of the fleeing vessels crashed into an asteroid and was separated from the fleet, stranded alone in space. Unable to make repairs, the crew placed themselves into suspended animation. When the asteroid was visited by the ship Star-Jammer, piloted by Thor and his fellow Asgardians while on a quest, the Kronans awoke and attempted to steal the Star-Jammer. Thor overcame the Kronans, destroying both their ship and the asteroid. Another Kronan vessel which numbered Korg and Margus among its crew was likewise stranded, and eventually conquered a Kree settlement in order to repair their ship; however, the ship was caught in the Great Portal, a space warp which brought them to the planet Sakaar, and the crew was separated in the crash.
Kronans were also involved in the consortium of extraterrestrials who attempted to negotiate the rights for the biography of Rick Jones, hoping that the book would reveal how Jones had once used the Destiny Force to halt the Kree-Skrull War, but the book was of no use to the assembled buyers. The Kronan mercenary Zardok served as a member of the Starblasters, an intergalactic band of pirates. He aided the Starblasters in the kidnapping of Kayla Ballantine, host of the Star Brand, and journeyed with the crew to the Stranger's laboratory world to have the Star Brand analyzed, but Kayla's lover Quasar assembled a team of Earth heroes to recover her, and the Russian god Perun apparently slew Zardok in combat. Some of the Kronans formed an alliance with the New Immortals, rogue creations of the High Evolutionary. They led an assault against the High Evolutionary's fortress at Mount Wundagore, but were defeated by Thor and the High Evolutionary's newest creations, the Godpack.Back on Sakaar, the Kronans were fitted with pain-inducing obedience disks and made to serve the forces of the planet's ruler, the Red King. Margus and the other Kronans fought the disks, and suffered massive brain damage that made them virtual zombies. Korg was selected for training as a gladiator, and was placed in a team consisting of the Hulk,Miek, Hiroim, Elloe Kaifi, Lavin Skee and a Brood. Korg wound up having to combat Margus and his fellow Kronans in a training session, and was forced to destroy Margus and the others to save his own life. The other gladiators who fought alongside Korg eventually chose to become "Warbound" after one of their number, Lavin Skee, was slain defending their lives. Acknowledging the Hulk as their leader, Korg and the other Warbound fought by his side in gladiator matches until the Silver Savage released them from their obedience disks. The Warbound became leaders of a rebellion, and ultimately toppled the Red King and installed the Hulk as the planet's new ruler. A trusted advisor to the Hulk, Korg was among the few who escaped Sakaar's destruction in a subsequent cataclysm; he and the other survivors have since joined the Hulk's war against Earth, whose heroes had apparently caused Sakaar's destruction.