Robert Bruce Banner was born as the son of Brain Banner who was an atomic physicist and his wife Rebecca. Brian hated Bruce, but Rebecca loved him. Brian was an alchoholic who was driven by an insane jealousy of Bruce for being an object of Rebecca's love. Further or more, Brian believed that his radiation work had altered his DNA and given him a mutant son. Brian then abused Bruce, finally murdered Rebecca, and was placed in a mental hospital. Bruce was a child prodigy who was raised by his aunt, Mrs. Drake and he internalizaed his great pain and rage over his childhood suffering thanks to his crazed father. After graduating from Science High School, Bruce Banner studied nuclear physics in Navajo, New Mexico, at Desert State University as the star student of Professor Herbert Josiah Weller. He also studied for a time at Pennsylvania State University, where he met Walter Langkowski who later became the Alpha Flight's Sasquatch. He obtained his doctorate in nuclear physics at the California Institude of Technology, alongside Phillip Sterns, who later became Madman. Eventually, as an adult genius in nuclear physics, Banner went to work at a United States Defense Department nuclear research facility at Desert Base, New Mexico. There, Banner met General Thaddeus E. "Thunderbolt" Ross, the Air Force officer in command of the base, and his daughter Betty Ross who he fell in love with. Bruce Banner designed and saw the destruction of the Gamma Bomb which was a nuclear weapon possessing a high gamma radiation output.
Banner was present in the instrumentation bunker at the test site for the first underground test detonation of the Gamma Bomb. Observing that a civilian had breached security and entered the restricted test area, Banner told his colleague Igor Starsky to delay the countdown while he tried to escort the civilian to safety. Starsky, who was secretly a Soviet agent, did nothing confident that Banner would die in the explosion, bringing the project to a halt. Reaching the civilian, a teenager named Rick Jones was thrown into a protective trench by Banner. Before Bruce Banner could get himself to perfect safety, the Gamma Bomb detonated and intense waves of radiation reached the surface. Banner was irradiated with highly charged radioactive particles. Due to an unknown genetic factor in his body, Banner was not killed by the radiation, but instead turned into a gray-skinned humanoid monster with more-than-large strength called the Hulk.