Robert Bruce Banner is the son of Dr. Brian Banner, an atomic scientist, and his wife Rebecca. Although Rebecca deeply loved Bruce, who returned her affection, Brian hated the child. Possibly an alcoholic, Brian Banner was driven by an insane jealousy of Bruce for being an object of Rebecca's love. Further, Brian Banner believed that his radiation work had altered his DNA and given him a mutant son. Brian Banner finally murdered Rebecca and was placed in a mental hospital. Bruce, a highly withdrawn, intellectual youth, was raised by his aunt, Mrs. Drake, and internalized his great pain and rage over his childhood sufferings.
Eventually, as an adult and a 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. Banner and Betty Ross eventually fell in love with each other. Banner designed and oversaw construction of the 'gamma bomb' or 'G-bomb,' a nuclear weapon that had 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 get the civilian to safety, Starsky, 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, Banner threw him into a protective trench. Before Banner could get himself to 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, which instead caused him to transform frequently into the vastly powerful, green-skinned named 'the Hulk' by the military present at the test site.
At first Banner changed into the Hulk at sunset and reverted to human form at dawn. However, Banner's body eventually changed so that his transformations into the Hulk were triggered by the release of adrenaline when he became intensely excited, no matter what time of day or night it was. Usually the Hulk possessed little of Banner's memory and intelligence and was easily enraged. Hence, the Hulk was a menace, continually hunted by military forces commanded by the implacable General Ross. For a short time Banner managed through radiation treatments to maintain enough of his own personality when he became the Hulk to control himself in that form, and he even became a founding member of the
Avengers in this form. But once again the Hulk lost Banner's intelligence and became a brutish menace. For a surprisingly long time Banner managed to conceal the fact that he was the Hulk, but his secret inevitably became public knowledge. For years Banner wandered the world as a hunted fugitive, cursed by his recurring transformations into the bestial Hulk.