Born as Kay Challis, the woman who would grow up to become Crazy Jane would suffer a horrific childhood. Starting when she was only five years old, Kay Challis was molested by her father. The first time this happened, she was putting together a jigsaw puzzle, and the image of the puzzle would imprint on her mind, and help her cope with her abuse years later. As her suffering continued, Kay eventually withdrew completely into her own mind, and is replaced by an alternate personality that went by the name "Miranda."
During one Easter Sunday years later, Miranda was sexually assaulted in a church, which triggers flashbacks to her former childhood abuse, and which ultimately destroys the "Miranda" personality. This results in a massive fragmentation of her psyche, like pieces of a jigsaw puzzle. Kay now developed at least 64 different personalities, some which were prominent, and others which were deeply buried. Soon after, Kay is committed to a mental institution when she can no longer cope with her trauma. It's during this time that the alien race called the Dominators invade the Earth, and attempt to active all the latent metagenes on the planet with what they call the "Gene Bomb." When it is detonated, almost all 64 of Kay's personalities develop super powers.
Each of Kay's personalities gained a different ability unique to them. There's the angry "Black Annis" who has razor sharp claws, Scarlet Harlot, who projects ectoplasmic bursts and absorbs sexual energy, and "Sun Daddy," a gigantic figure with a sun for a head and with the ability to create fireballs. And these are just the tip of the iceberg. The dominant personality goes by the name Jane Morris, who is later given the nickname Crazy Jane, an homage to a famous 19th century painting and a series of poems by William Butler Yeats.
All of Crazy Jane's various personalities are organized in sort of mental subway grid which she refers to as "the Underground." Within this Underground, each of her personalities has its own station, which functions as their home when they are not in control of Kay's physical body. Within the lower depths of the Underground is what Jane calls "the Well," a reference to her abusive childhood, where the personalities go to destroy themselves, and where Miranda was extinguished. The conductor of the Underground has its own personality, and is known as "Driver 8."
The Super-Hero Cliff Steele, also called Robotman, suffered terrible losses during the alien invasion, which killed several of his Doom Patrol teammates, and as a result, he was suffering emotionally. While staying in the same institution as Jane, Dr. Will Magnus, creator of the Metal Men, asked Cliff to look after her, as she was coping with becoming a metahuman. This ultimately led to Jane being asked by Dr. Niles Caulder into becoming a member of the new Doom Patrol.
As a member of the Patrol, Jane formed a close bond with Cliff, during an era when the team had many wild adventures, fighting against the likes of the Brotherhood of Dada, the Scissormen, and the Beard Hunter. The team eventually settled in a place called "Danny the Street," a living transvestite street, with which Jane found a particular affinity for. During her time with team, Jane journeys back to the home she lived in as a child, and she confronted her own traumas and eventually overcame them. Because of her newfound inner peace, her personalities integrate into different facets of a more complicated single being.
During one Doom Patrol adventure, Jane was attacked by the creature known as the Candlemaker, who tossed her into another dimension. In this world, which was similar to ours, she was diagnosed as being schizophrenic, and tortured with shock therapy. Cliff was finally able to rescue Jane from this dimension, and he and Jane relocated to the newly dubbed Danny the World. Not long after, it was revealed that all of Jane's other personalities actually still existed, which led to many arguments with Cliff. He left Danny the World and returned to Earth, but Jane stayed behind
When a group of cross dimensional gentrifiers tried to alter Danny the World to their own liking, he reconfigured himself into Danny the Brick to escape them. Jane returned with Danny to Earth, and sought sanctuary with her old friends the Doom Patrol, now residents of Oolong Island. During this time, yet another personality of Jane's makes itself known. This personality starts a cult and plans to spread Jane's personalities among the sixty-three cult members, and then kill the cultists. The Doom Patrol stops her, and the Jane Morris personality returns and dominates the other 63 personalities once more. Jane now fully accepts her mental illness, and instead of trying to cure it or suppress it, she has chosen to simply try to manage it.