When Corsair and Katherine Summers were kidnapped by the Shi'ar alien race their two children Scott ( Cyclops) and Alexander ( Havok) were left behind on Earth. At the time Katherine was pregnant with her third child. During a failed escape attempt by Christopher (Corsair), Katherine was murdered and her unborn child was cut from her womb as a punishment. The child, Gabriel, was believed to be dead. In reality D'Ken saved the child and kept it alive with advanced Shi'ar technology and artificially accelerated his aging in order make him a slave. When Gabriel became older he was sent to Earth as a slave for Eric The Red where he was able to escape. He was found by Moira MacTaggert with little memory of his past and extended an invitation to join a team of young mutants that she would train in the use of their powers. He took the name Vulcan after the Roman god. Professor X recognized Vulcan's relationship with Cyclops using his psychic powers and was able to reunite the brothers.
Later, when the original team of X-Men were sent to a remote island in the pacific ocean to investigate the signal of a powerful Mutant that was detected by Cerebro. The team was captured by the island, which turned out to be the source of the mutant signal. The island, Krakoa, held the X-Men save for Cyclops who was able to escape. From there it was originally believed that Professor X collected the all-new all-different X-Men from around the world to rescue the original team. What was not known at the time was that there was this team was not Xavier's first rescue attempt. Moira MacTaggert's team was much less skilled and experienced than the X-Men themselves and consisted of the mutants Petra, Sway, Darwin, and Vulcan. Xavier recruited Moira's team to be the next team of X-Men, and also met with the a young Emma Frost to offer a position on the team. Emma, who was not ready for the X-Men at the time refused and Xavier and Vulcan left her with the Hellfire Club. While leaving Xavier erased her memory of the encounter. With little time to spare, Xavier used his telepathy to train the team psychically, allowing them to train in the use of their powers in their minds. The duration of this training felt like it was extended, while only lasting a period of hours in the real world.
When the team, led by Vulcan, was sent to Krakoa to rescue the original X-Men they were quickly subdued by the island. Vulcan was able to survive by absorbing the powers of his teammates, buried deep in the island. When the island was shot into space by the second rescue team, Vulcan remained on it in stasis, kept alive by Darwin's powers. Because of the X-Men's heavy emotions over what had occurred Xavier used his telepathic powers to erase the memories of everyone involved, leaving no trace of recollection of the original team.
After the events of the House of M, 90% of the world's mutants were de-powered by the Scarlet Witch. This surge of power released into the universe when the so many mutants lost their powers caused Vulcan to stir, still inside of the island which was orbiting the Earth. Realizing what had occurred Vulcan felt betrayed by Xavier. Wanting to make Xavier pay for his deception Vulcan sought to drive Xavier out (who Vulcan did not know had not been seen since M-Day). Vulcan, whose powers are now at Omega-level mutant, first killed Banshee by hitting him with a plane. He drew Cyclops and Wolverine into a cave with the image of their beloved Jean Grey, and quickly bested them in combat. Vulcan captured Cyclops and Marvel Girl and imprisoned them in the facility where Vulcans team originally trained with Cyclops. After barely escaping, Vulcan confronted the team, including Xavier, about what happened. Professor X, who had lost his powers on M-Day could not show the team what had actually transpired as Vulcan demanded. Rachel used her telepathic abilities to link the minds of the X-Men with the Professor so that he could show them what actually happened.
The team attacks Vulcan for killing Banshee, but Vulcan escaped into outer space. Vulcan, who had spent his childhood imprisoned by the Shi'ar as a slave, left for Shi'ar space to make them pay for killing his mother and for his difficult childhood. Horrified by the betrayal against both teams of X-Men, Cyclops tells Xavier that as a human he is no longer welcome at the Xavier Institute for Higher Learning.
Giant-Size X-Men #1
X-Men: Deadly Genesis #1-6
House of M - The events of the Deadly Genesis are preceded by the House of M, although other than the link mentioned there is no real relationship between the stories.
Rise and Fall of the Shi'ar Empire - The events that occur directly after the Deadly Genesis storyline, beginning with Vulcan heading into Shi'ar space to exact his revenge.
Non U.S. Editions