Batwoman is primarily associated with the Silver Age of comic books. She first appeared in Detective Comics #233 (July 1956). She was a costumed crime-fighter like Batman, his counterpart in many ways. For example, while Batman wears a utility belt, Batwoman carried a utility purse.
Batman co-creator Bob Kane later claimed that he originally drew her to resemble his wife. The fact that he named her "Kathy Kane" supports this statement; however, Kane used "ghost pencillers" such as Sheldon Moldoff and Dick Sprang to draw most Batman comics in the 1950s, and the question of how much input Kane actually had to the Batman stories is disputed.
Batwoman guest-starred occasionally in Batman stories published from 1956 to 1964. Batman wished for Kathy to retire from crimefighting due to the danger. Nevertheless, she remained his ally (even when she temporarily became a new version of Catwoman).
In 1961, Batwoman was joined by her niece Betty Kane, the Bat-Girl, named after Bob Kane's wife. Kathy and Betty were romantically interested in Batman and Robin, respectively. Robin seemed to return Bat-Girl's affection, while Batman remained aloof.
In 1964, DC dropped Batwoman, as well as Bat-Girl, Ace the Bat-Hound, and Bat-Mite from the Batman titles, which were undergoing a revamp under Editor Julius Schwartz that eliminated elements considered too "silly". In stories published during the next few years, Batwoman makes several appearances in the Batman-Superman team-up book World's Finest, which was edited by Mort Weisinger.
In the 1970s, Batwoman only appeared a few times, often fighting crime alongside the second Batgirl Barbara Gordon. During her retirement, she becomes the owner of a circus, which she kept until she died. She is killed by the League of Assassins and the brainwashed Bronze Tiger in Detective Comics #485 (September 1979).
There was also a Batwoman on Earth-Two, who was very much like her deceased Earth-One counterpart. This Kathy Kane retired when the Batman of that world married Catwoman. She married and had children, but her husband was never revealed. She came out of retirement following Batman's death when Gotham City was threatened by the return of Hugo Strange