Henry Pym was a brilliant scientist who spent much of his time in his lab. Upon his creation of Pym particles, he found himself shrunk and had to escape from an ant hill. He began to adventure as Ant-Man, and often ran up against the villain Egghead. About the same time, he created the robot Ultron-1.

Soon, he met and married the beautiful Maria Travonoya. Unfortunately, when in her home country of Bratislavia, she was captured by revolutionaries, and, despite Pym's efforts, she was killed. Later, he was contacted by the father of Janet Van Dyne to help Van Dyne in his scientific experiments, and he soon fell in love with Janet. When her father was captured by the aliens he was trying to contact, Pym as Ant-Man came to rescue him. Ant-Man revealed his identity to Janet, and Pym convinced her to join him as his partner, engineering her body to become the Wasp.

Ant-Man and the Wasp were on hand to battle the Hulk with Thor and Iron Man, when the Wasp suggested they form a team, the Avengers. Pym continued to fight alongside the Avengers, but soon felt outclassed by the powerhouses of the team and created the identity of Giant-Man. Later still, Pym proposed to Janet, and the two breifly left the team for their marriage. One way or another, Pym found himself back in the Avengers, and in the other identity of Goliath. He usually wanted to stay in his lab, and adventured with the Avengers because the Wasp always wanted to.

Trying to be more formidable still, Pym developed the Yellowjacket identity. He tried again to drift away from the Avengers, but Wasp offered their services again. Pym, at the same time, was undergoing severe mental stress, and began to have a nervous breakdown. At one point, he even struck Janet, and later, during battle with the Elfqueen, lashed out at the villain just as she was about to surrender. The Avengers began a courtmartial process for Pym, who, losing his sanity, created a robot to destroy the Avengers-- but built with a failsafe that Pym would activate to "save" his friends and regain his status. The ploy failed, and the Wasp, who discovered Pym's treachery, saved the team. Pym promptly quit, and the Wasp filed for divorce. Pym was further oppressed as his old enemy Egghead framed Pym for stealing nuclear devices, imprisoning him. Egghead led the Masters of Evil in freeing Pym from his trial, further implicating him in villainy. Pym soon defeated the Masters singlehandedly, redeeming himself but not rejoining the Avengers, although he later would ally with them if his expertise was needed.

Later still, Pym found his body could not handle the stress of constant size-changing, and retired from costumed crime fighting. He still joined the Avengers, however, when they opened their west coast branch, in order to oversee the facilities and the scientific research. Growing more despondant, however, he soon decided to commit suicide, but was stopped by Firebird (then Espirita,) who helped him to reconcile the two areas of his life-- costumed crime fighting and scientific research. As plain Hank Pym, he would use his shrink field to shrink and grow equipment around him, and he joined the Avengers full time.

Although he stayed with the west coast branch for some time, Pym soon found himself actively in the New York mansion. Later still, Pym and other size-changing heroes were caught up in an invasion attempt from their mass-displacement dimension. The outcome left Pym able to grow again (but not to shrink,) and he resumed his old Giant-Man identity. Pym was on hand with the other Avengers who seemingly sacrificed their lives to absorb the energies of Onslaught. Actually transported in another dimension, Pym's new self adopted the Ant-Man identity again, before being transported back to our dimension.