As a young boy Alexander Summers was enjoying a normal life with his parents and brother until one fateful day. His father, Christopher Summers, was flying his family back home from vacation. The small plane happened to run into a Shi'Ar scout ship. The ship began to attack the plane, a near miss set the plane afire. Christopher was forced to send his two boys out of the plan with the only remaining parachute. Alex and his brother Scott plummeted from the plane in a burning parachute. Alex believed that his parents had died when in fact his father and mother, Katherine Summers, had been captured by the Shi'Ar Empire.

The boys both survived the fall, but were hospitalized due to their injuries. He remained in the hospital for two weeks and was transferred to an Orphanage in Omaha, Nebraska after his recovery. The orphanage was run, unknown to the general populace, by Mr. Sinister who arranged to have Alex adopted so that he would be separated from Scott. Alex found his way into a new family and lived a normal childhood.

Alex was reunited with his brother when he graduated from college. It was at this time that he first became aware of his latent mutant powers. A professor of Archeology named Ahmet Abdol was also a mutant with a link to Havok. The Living Pharaoh, Abdol's alter-ego, absorbed cosmic rays like Alex. Alex's body somehow affected the absorption of rays by Abdol. As one became more powerful the other's powers waned. In order to gain greater power the Living Pharaoh took Alex to Egypt locking him in a cell that blocked the cosmic rays. Alex nearly died while locked away, but found his full powers returned when the Living Pharaoh was defeated. Unable to fully control his powers Alex chose to remain in the Egyptian desert where he would not harm anyone.

While traveling in the desert Alex was captured by a Sentinel and taken to Larry Trask. Trask provided Alex with a costume and the name Havok. The costume would display the levels of energy that Alex had absorbed allowing him a better view of when he needed to release his powers. The X-Men attacked Trask and succeeded in rescuing Alex. He traveled back with his brother and the rest of the X-Men to the mansion where he was able to gain a better control of his powers. Alex soon found himself in love with Lorna Dane, the mutant Polaris. The two shared a lack of interest in the life of a costumed hero. They moved to the Diablo mountain range in Arizona to work on their doctoral studies. They had hoped to be able to live a normal life free from the adventure that others sought.

Their simple life did not last long as they were soon approached and hypnotized by a Shi'ar agent in the guise of Eric the Red. Eric the Red took Polaris and Havok with him to battle the X-Men. Havok fought on the side of Eric for a short time when he was not operating under his own free will. After the incident with Eric the Red, which led to the return of Magneto, Alex and Lorna returned to Arizona to continue their studies.

When Magneto took over the X-Men Alex made a visit to ensure that everything was normal. He found no unusual occurrences and returned to Arizona. After his return he began having nightmares about being attacked by the X-Men. At one point the nightmare became so strong that he awoke needing to release energy, Havok sent a full blast of his powers in order to release the stored energy. It was at this point that he realized that he needed to travel back to New York and find the X-Men. Upon returning to New York Alex arrived at an empty mansion.

Alex confronted Magneto, the new White King of the Hellfire Club, and was told that the X-Men agreed with his decisions. Alex, not believing Magneto, began searching for the X-Men. He eventually found the remaining X-Men in the sewers that were once home of the Morlocks. He learned that the X-Men had planned to fake their deaths so that their loved ones would be free from danger. Faced with a difficult decision Havok agreed to rejoin the X-Men, with the fear of how he would explain this decision to Lorna. Alex soon found out that Lorna had been taken over by the entity Malice and thus his decision to join the X-Men was sealed. Malice was able to further hurt Havok by manipulating him into firing at Polaris.

Soon after joining the X-Men Havok "died" with them during the Fall of the Mutants. It was after this death that he and the X-Men began secretly operating out of Australia. It was while in Australia that a relationship grew between himself and Madelyne Pryor, his brother's wife. Madelyne soon became the Goblin Queen and enlisted Havok's help in defeating the X-Men. This time period known as Inferno gave Havok a greater sense of control over his powers.

Havok and the rest of the X-Men entered the Siege Perilous, a gem that would allow those who were worthy enter and be remade in a new life. They would find themselves in the life of their dreams. For Havok he ended up as a soldier in Genosha. His memories and past identity only returned after Psylocke stabbed him with her psychic knife. Havok left Genosha to join the government supported group X-Factor where he became the field leader and was reunited with Lorna. He currently serves as X-Factor's field leader but is undergoing physiological changes which are affecting the control of his powers. Though his current location is unknown, Havok has been captured by Bad Beast.

Havok recently "died" in the real Marvel Universe, and was transported into the body of the Havok of another world, who died as well.