A hero published by Marvel Comics. Havok first appeared in The Uncanny X-Men #58 in 1969.

Alex Summers was the younger son of Major Christopher Summers and his wife Katherine. Along with his brother Scott, the family was traveling in a small plane when it was attacked by a scout ship of the Shi'ar empire. The parents were transported aboard the scout ship, while their sons sought escape using a single parachute. The parachute, damaged from the destruction of the plane, slowed their fall, but the subsequent injuries placed Scott in a coma for a time. During the aftermath of this event, Alex was placed in an orphanage and later adopted and he and his brother would not see each other for many years to come.

Scott was recruited by Charles Xavier to become part of his X-Men and for many years adventured with that team. Meanwhile, Alex grew up unaware of his burdgeoning mutant powers. While attending college, Alex came to the attention of one of his professors, an Egyptian named Ahmet Abdol. Abdol was proud of his Egyptian heritage to the point that he was not content with a Kiss me, I'm Egyptian t-shirt and instead wanted to lead the Egyptian people back into their heyday. To this end, Abdol sought power and discovered that he had a mutant ability which could potentially give him great power. He also discovered that this mutant ability was being blocked by another mutant with whom he had an inexplicable psychic connection: Alex Summers. The fact that Summers was one of his students and not a produce manager in a Publix grocery in Conyers, GA was an amazing stroke of luck for Abdol.

Abdol kidnapped Summers and flew him to Egypt where he equipped him with a device that blocked Summers absorption of cosmic waves. The result was that Abdol grew to gigantic size and renamed himself the Living Monolith. Abdol battled the original X-Men who had come to rescue Summers, but was defeated when Alex Summers' mutant ability surfaced and he began to release waves of cosmic energy that caused massive explosions. The problem was that Summers was unable to control his new powers and so decided to stay in the Egyptian desert for the safety of others.

Soon afterward, Alex was captured by Larry Trask, the son of the inventor of the mutant-hunting Sentinels. Trask fitted Summers with a costume that kept his powers in check and monitored their build up by displaying concentric circles on his chest. The larger the circles, the more power was being built up. Trask also dubbed Summers Havok due to the violent nature of his ability.

Trask and his Sentinels battled the original X-Men and were defeated and Alex and his brother Scott were reunited. Havok worked with the X-Men for a time, learning to control his powers and sharing in a few adventures with him. During this time, Havok fell in love with Lorna Dane, the mutant heroine Polaris. The two decided to make a life for themselves outside of the X-Men's life of adventure and settled in the desert Southwest to work in geophysics.

So the couple lived for many years with only a few adventures to interrupt their peaceful existence. But, Polaris was targeted by one of the Marauders Malice and was possessed by it for a time. During this time Havok joined the X-Men and adventured with them. He fell in love with Madelyne Pryor, the estranged wife of his brother Scott. When Madelyne's bitterness over her failed relationship with Scott was used as a leverage by the demon Nas'tirh to transform her into the Goblin Queen, Alex was caught in the middle of the subsequent battle.

Soon afterward, Psylocke convinced her fellow X-Men to enter the Siege Perilous, a mystic device that caused the mutants to be "reborn' with no knowledge of their former lives. Havok ended up being a member of the police force for the Genosha government, an island nation where mutants lived as second class citizens. When forces from Genosha attacked and captured members of the X-Men and New Mutants, Havok came into conflict with his fellow friends and eventually regained his memory.

Havok later became the leader of a U.S. government team of mutants known as X-Factor. During this time, he was reunited with his former lover Polaris who was freed from her control of Malice. Havok worked with X-Factor for many months, until the apparent death of his teammate Jamie Madrox. Disillusioned by the efforts of the X-Men and X-Factor to make a difference, Havok seemingly turned evil and began working with Hank McCoy's evil counterpart from another reality Dark Beast. The two organized a group of evil mutants called the Brotherhood, but Havok actually was keeping tabs on the Dark Beast's activities and helped to defeat him.

Soon after this, Havok was seemingly killed when the plane he was flying in exploded. In fact, his body was thrown clear and was in a coma. Meanwhile, Alex's soul found its way to another dimension, similar to our own, but different. There Alex became a member of a hero group called the Six made up of fellow mutants who were Alex's friends, but these mutants were different than he knew. Alex battled the evil forces of this reality until he was forced to sacrifice himself to stop a force that threatened that reality an all others. The result was that Alex's soul was once again set adrift, until it was reconnected with his body by a young mutant.