In 1939, Bill Finger and Bob Kane introduced the world to one of the most famous fictional characters of all time in Detective Comics #27, Batman. Over the next several years, the Caped Crusader would defend Gotham's streets and America for over a decade.
However, Showcase #4 introduced the world to a new Flash named Barry Allen in the '50s, and the Golden Age heroes of the DC Universe have quietly shuffled away into their own world: Earth-Two. Their tales would continue, however, and DC eventually allowed their 1940s stars to feature periodically in their own stories, creating one of the first looks into Batman's long-term future.
The Golden Age Batman's origin contains only a few key differences to the ones most fans know today. His parents were still murdered, but in this reality, that killer was successfully identified as Joe Chill. After his parents' death, Bruce is taken in by his uncle Phillip Wayne, not Alfred. After vowing to honor his parents with a war on crime, Bruce trains to become a police officer but is stopped by his girlfriend, Julie Madison, who refuses to be with someone who constantly risks their life. To keep his vow and stay with Julie, Bruce decides to fight crime in secret as the Batman after a bat flies through his study's window.
The Batman soon stalked his city's darkened streets, defeating Doctor Death, the Monk, Hugo Strange and his Monster Men, killing many evil-doers along. His adventures began to lighten up when his creators began appealing to younger readers by introducing Robin the Boy Wonder as Batman's sidekick. Together, this Dynamic Duo fought Two-Face, Joker, and Catwoman, befriended Superman, and co-founded the Justice Society of America.
After intermittently helping the Allies throughout World War II, the Batman permanently returned to the United States and continued to defend Gotham even after the Justice Society was disbanded for refusing to reveal their secret identities. On one of these adventures, Catwoman sustained a head injury that unlocked secret memories which eventually led her to reform, retire from crime, and open up her own pet shop in Gotham City.
Batman and Catwoman revealed their identities to each other, began a romantic relationship, and were eventually married, giving birth to a daughter named Helena Wayne soon after. With her birth, Bruce decided to follow one major life change with another and retired from his adventures as Batman to become Gotham's new Police Commissioner, thus ensuring that Helena would not suffer his childhood's fate.
Dick Grayson continued Batman's crusade as an adult Robin and even took Bruce's place in a reformed JSA, but the Wayne family's happiness would not last forever. When Helena was 19-years-old, one of her mother's old enemies returned and killed Catwoman, despite Bruce's best efforts. In Paul Levitz and Joe Staton's DC Super-Stars #17, this tragic loss inspired Helena to become the Huntress and bring her mother's killer to justice alongside Robin as a new Dynamic Duo.
Bruce Wayne served as Gotham's Police Commissioner until his death at the hands of a super-powered maniac in 1979's Adventures Comics #462, by Paul Levitz and Joe Staton. Unable to stop him, the Justice Society was on the verge of defeat when Bruce Wayne took up his cowl one last time and turned the maniac's own powers against him, killing them both. Bruce was buried beside his parents and his wife, and Robin and Huntress vowed to continue his crusade, though neither of them took on the "Batman" name.
Still, in America vs. the Justice Society, death was unable to stop Batman from protecting Earth-Two one last time. Dick Grayson eventually discovered a set of diaries written by Batman that indicated the Justice Society had secretly collaborated with the Nazis during World War II. During the ensuing court battle, however, it was discovered that the diaries were fake and all part of a scheme by Bruce to thwart the time-traveling plot of the JSA-villain Per Degaton. With this discovery, the JSA was acquitted, Per Degaton was defeated and Batman kept Earth-Two safe for the last time.