Alexander Summers is the son of Major Christopher Summers, a test pilot for the U.S. Air Force, and his wife Katherine Ann Summers. His older brother is Scott Summers. Both are mutants.
When Scott and Alex were boys flying home from a family vacation in their father's vintage private plane, a scout ship from the alien Shi'ar Empire suddenly materialized and set the plane ablaze. Katherine pushed Scott and Alex out the plane door with the only available parachute. The parachute caught fire, so Scott used his mutant optic blasts for the first time to slow their descent. Scott and Alex were unaware that their parents had been teleported from the plane by the Shi'ar a moment before it exploded.
Scott suffered a head injury on landing that damaged the part of Scott's brain that would have enabled him to control his optic blasts. The two boys were hospitalized and both suffered traumatic amnesia regarding the incident.
They left the hospital after two weeks and were placed in the State Home for Foundlings, an orphanage in Omaha, Nebraska and were subjected to a battery of tests and experiments by the orphanage's owner, Mr. Milbury, an alias for the evil geneticist and their future enemy Mr. Sinister. Sinister believed that Scott was the Summers brother with the most potential, so he had Alex adopted to separate them and render Scott emotionally vulnerable.
Alex had little or no contact with Scott until years later. Alex was raised by Andrew and Joanna Blanding, whose son Todd had been killed in a car accident. Alex was pressured to act as a replacement Todd, which he tried to do as best as he could.
When Todd's killer Vincent kidnapped Alex and his foster sister, Haley Blanding, Alex manifested his mutant powers for the first time, incinerating Vincent. Mister Sinister appeared, quite surprised to find that Alex?s potential possibly exceeded Scott's. Unfortunately, Alex lacked any control over his powers. Sinister placed psi-blocks on both Alex and Haley, causing them to forget everything that happened that night.
The immortal mutant Apocalypse encountered the non-mutant variant Ahmet Abdol and deemed him to be a broken, beaten man of great potential but without direction. Apocalypse acquired a sample of Alex Summers' DNA, insuring that its coding had been modified for his purposes, and had Sinister graft it to Abdol. The experiment was only partially successful and resulted in an unexpected and quite unusual symbiotic relationship wherein Abdol's power was split between them and not shared. Deciding to use his powers for his own personal gain, Abdol created a cult around himself as messiah, the Cult of the Living Pharaoh, became a super-villain and set about his plan to rule the world.
Alex grew into an adult unaware of his brother's developing mutant power or his identity as Cyclops, leader of the X-Men, until after Alex graduated from Old Landon College's geophysical studies. Ahmet Abdol, then a professor of archaeology, discovered a psychic link between himself and Alex. While both of them possessed the latent mutant power to absorb and transform cosmic radiation, Abdol's ability to exercise the power was jammed in an unknown manner by Alex' body. Abdol captured Alex and took him to his laboratory in Egypt.
Abdol found a way to screen Summers' body from ambient cosmic radiation, permitting his own body to attain its latent potential. Abdol was transformed into the Living Monolith, a gigantic mutant with vast cosmic power. The Monolith was defeated while in combat with the X-Men when Alex's latent mutant powers surfaced under the stress of entombment within the mechanism designed to screen him from cosmic radiation.
Incapable of controlling the shock waves his body emanated, Summers chose to remain in the Egyptian desert, rather than accompany the X- Men back to America. Summers was soon captured by one of the mutant-hunting robotic Sentinels and brought to the headquarters of Larry Trask, the son of the Sentinels' inventor, Dr. Bolivar Trask. Trask gave Summers the codename Havok and a costume, whose chest display monitored the build-up of cosmic energy within him. When the X-Men finally freed Trask's captive mutants, Havok was severely injured.
Alex accompanied his brother and his teammates back to the Xavier's School for Gifted Youngsters, where he began training to help him keep his energy in check. While with the X-Men, Havok was immediately attracted to the green haired Lorna Dane, much to the anger of Iceman, who also showed a romantic interest in her. Professor Charles Xavier enlisted Alex and Lorna's help repelling an invasion by the alien Z'Nox. Later, Havok and Lorna met Ka-Zar in the Savage Land, were targeted by the Promise, and encountered the Hulk who mistook Lorna for his former lover Jarella.
Havok gained enough mastery over his power that he could release it only when he wished to do so, as opposed to when he was near death, and could wield his power skillfully enough to become a formidable opponent in battle. Following the X-Men's battle against the island Krakoa, Havok and Lorna left the X-Men to pursue their mutual interest in geophysics, attending graduate school in Nevada.
Afterward, they settled in New Mexico, where they completed their advanced degrees. Their plan to stay out of the affairs of the outside world did not last long as Professor X called on Alex and Lorna for help in the rescue of the friends and family of the X-Men from Arcade's henchman Miss Locke in Murderworld.
Scott brought a visitor to meet Alex, his long lost father, who had become a space pirate called Corsair. Corsair had been captured and sold into slavery by the Shi'ar Empire and later became leader of the Starjammers. Alex learned his grandparents were still alive and owned a shipping company in Canada. At the Summers family reunion Scott was shocked to meet Madelyne Pryor, a pilot for his grandparents who was identical in appearance to Scott's late love and former X-Man Jean Grey. No one was unaware that Madelyne was a clone of Jean created and programmed by Sinister to fall in love with Scott to make use of their potentially powerful offspring for his own purposes. Scott and Madelyne did grow close and Alex attended their wedding as his best man.
Alex, some of the original X-Men founded X-Factor, an organization that intended to seek out and aid mutants under the pretense of hunting down mutants as "actual" menaces to society.
While Havok was away the Marauders went after Polaris. The psychic entity Malice possessed her body and assumed leadership of the Marauders. Havok ran into Polaris/Malice in San Francisco when she was attempting to kill Madelyne Pryor who was still in a hospital. Malice made Alex aware of the fact that Lorna was being controlled and tormented him with the knowledge that he could do nothing about it.
In Dallas, Texas, the X-Men and Madelyne Pryor gave their lives to imprison the Adversary. The Omniversal Guardian Roma restored the X-Men to life. The event was broadcast live on television and the world believed the heroes to be dead. After being resurrected, the X-Men decided to go underground and keep their rebirth secret. The X-Men resurfaced in Australia, where they defeated the Reavers and claimed their base. Roma magically made them invisible to any sort of detection such as cameras.
The X-Men next investigated the Brood Star-shark Havok had found and tracked the source to Harry Palmer, who was unaware he was infected and had made an entire cr?che of mutant hosts. The X-Men were conflicted over killing the human hosts, but Havok was forced to kill several of them. He was left to wonder if killing becomes easier each time. Alex began to feel remorse for the lives he had taken, feeling that he was becoming more like Wolverine and resented the idea.
Malice's hold over Polaris weakened due to the death of Sinister. After Lorna freed herself from Malice, she called the X-Men (including Havok) for help from the southern-most tip of South America, only to be captured by Zaladane. Psylocke knew that returning to their Australian base was certain death, however the teleporter Gateway called the X-Men back (leaving Polaris stranded in South America) without being asked. Roma had presented them with the Siege Perilous, a gem that created a portal which granted any person who walked through it judgment and a new chance at life, with a new career, home, and so forth. Psylocke persuaded the Havok and the rest of X-Men to walk through the Siege Perilous rather than die at the hands of the Reavers. Lorna eventually regained her freedom and headed to Muir Island.
Havok's X-Factor costumesource: http://www.angelfire.com/comics/benriely/
http://www.comicvine.com/havok/4005-3546/
http://marvel.wikia.com/Alexander_Summers_%28Earth-616%29