She began life as one of the few superheroes to appear after the Golden Age of Comix but before the Silver Age got underway. She came about because of the reactionary politics and homophobia of the 1950s—- but when they remade her for the twenty-first century, she became the most prominent lesbian in mainstream comics, actually inheriting DC Comic's namesake title.1
"That's not Batgirl..." thinks hardboiled detective Renee Montoya, when the character makes her second debut. "That's a Batwoman! Hot damn!"
In 1954, Dr. Fredric Wertham published Seduction of the Innocent, a sensationalistic attack on comic books which made headlines and turned the conservative psychiatrist into the toast of the PTA circuit. Among his many charges: comic books encouraged homosexuality and sadomasochism.
Batman and Robin, in particular, were "a wish dream of two homosexuals living together." Although Bruce Wayne always had lots of gals in his belfry, DC comics decided the Dynamic Duo needed girlfriends while they were in costume as well. To that end, Bob Kane and Sheldon Moldoff created the original Batwoman (at times, Bat-woman) in 1956; Batgirl was added a few years later.2 The first Batwoman, Kathy Kane, was a wealthy heiress and former circus acrobat who wore a bright yellow and red, vaguely bat-like costume and carried a utility purse. Her niece, Betty Kane, joined her on visits as Batgirl. She dressed in a red and green costume that recalled more than a little a girl's Phys Ed outfit of the era. Neither could have been very successful at sneaking around. They were costumed adventurers with crushes on Batman and Robin, and as likely to require saving as save the day. They appeared sporadically into the early 1960s, when editor Julius Schwartz banished them both, along with Bathound, Bat-Mite, and other batty accouterments the era had foisted upon the Dark Knight. Of course, a far more popular Batgirl, Barbara Gordon, soon flew into the Caped Crusaders' lives courtesy of the 1960s television series.
Both original Bat-females reappeared briefly in the 1970s; Kathy Kane ultimately died in Detective Comics #485.3 Crisis on Infinite Earths (1985) retroactively wiped both characters out of continuity. Nevertheless, a wealthy Kathy Kane turned up a few times after Crisis, and both Eisenhower era Gothamites appear, enigmatically, in a picture in the Batcave in Batman: The Killing Joke(1988).
Batwoman reappears in 2006. This time, she calls herself Katie Kane, has the bright red hair so common to comic-book females, and she brings elements often suppressed by comic-book heroes to the forefront. Most major superheroes were created by Jewish artists and writers, but they were given vaguely Protestant backgrounds in order to suit the broader American audience. Katie, however, is expressly Jewish. Gay characters have only gradually surfaced in comic books; this Batwoman is identified as lesbian from the outset.
Like her more famous role model, Batman, she has several adventures before we learn much about her origin.4
The Penguin foreshadows her debut in Detective #824, where he mentions a "hot" new Batwoman working in Gotham City. We finally see her in 52 #11, first as Kathy Kane. She's an attractive but very broad-shouldered and well-muscled femme opposite her ultra-butch ex-girlfriend, Renee Montoya, hitherto DC's most prominent gay character. We learn little about her: her family has money, she's a bit of a bohemian, and her relationship with Montoya occurred some years earlier, when both were in their early twenties.
Later that issue Kane as Batwoman helps Montoya and the Question against members of the Religion of Cain. In a plausible development that almost never happens in comic books, Katie's ex immediately penetrates her disguise and recognizes her under the black-and-red costume. As 52 and the subsequent spin-off, Crime Bible unfold, we learn that she holds significance to the criminal Religion of Cain. Their prophecies speak of a "twice-named daughter of Cain." Katie's name is "Kane," and she has two identities.
Actually, she was once one of a pair, as we later learn.
After a handful of appearances, Batwoman took over the lead feature of venerable Detective Comics with issue #854 (2009). As her adventures progress, we finally learn her personal history.5 She is one of a pair of tough twins, born to a military Colonel. Significantly, the young girls choose as their role model Superman, who must at this point have recently made his debut.6 Katie, her sister, and their mother are kidnapped by a terrorist group; the crossfire of the rescue operation apparently leaves Katie the sole survivor. Later, she follows her father's footsteps to West Point. Her superior mental and physical abilities make her one of their most successful female candidates ever. The Military Academy nevertheless discharges her when she refuses to lie and deny accusations of homosexual conduct. By then, her father has remarried a wealthy woman and they've furthered their fortune, mainly through real estate deals. The Colonel is now the second-wealthiest man in Gotham, after Bruce Wayne.
Depressed and unable to serve her country, she begins drinking and living the life of a wealthy socialite. She meets the young Renee Montoya (not yet a detective), and they begin a relationship. Montoya also teaches the trained soldier a few new fighting techniques she's learned on the street. Later, Katie uses her physical skills to dispatch a would-be mugger, and has a brief encounter with the Batman.
She recognizes her destiny, and she realizes she has the resources to make it possible. She receives additional help from her father and his military connections, and she chooses a costume inspired by Gotham's most famous crimefighter, so that everyone will know whose side she's on.
The track record for female turns on Batman has not been strong, but this one has achieved considerable popularity. Her adventures generally have been well-written, and if few comic-book females entirely dodge charges of sexual exploitation, Batwoman has been handled reasonably. Her costume has the form-fitting aspect of most conventional super-outfits, but it's not the stripper gear often worn by masked female vigilantes. She's attractive but also muscular, and her proportions have not been particularly exaggerated. Her personal life rates as much mention as does that of many contemporary characters, and has been handled without excessive prurience. Unlike the family of Renee Montoya (with whom she often works), her father accepts her lesbianism. As for Montoya, who took on the Question's identity and powers when the original died, she holds down Detective's back-up feature. In 2009 and 2010, one of the longest-running and most influential comic books in history spotlighted two gay characters. Late in 2010, Batwoman received her own title.
Take that, Dr. Wertham!
Note: Updates follow the footnotes.
1.DC takes its name from Detective Comics, one of their first successes and the first comic to be dedicated to a single subject: detective/police work. Detective's first issue appeared in 1937, making it the longest-running American comic and the second-longest-running comic book anywhere in the world. Its other claim to fame is, of course, the introduction of Batman in 1939.
2. Bat-woman first appears in Detective #233; Batgirl turned up in Batman #139.
3. An alternate-reality Batwoman also appeared once in The Brave and the Bold #182, set on "Earth-2."
4. Batman's origin has become so intertwined with his character that it surprises many readers to learn no one thought to give him one when he first appeared. Bill Finger, whose work on Batman shaped him as much as did creator Bob Kane's, added the sad tale of the Waynes a few stories into the Dark Knight's history.
5. Most of her life story has been taken from Detective, but some elements come from her earlier appearances. 52, for example, establishes that Montoya taught Kane some fighting techniques while they dated.
6. We can surmise their admiration from the fact that they're wearing Superman t-shirts to bed. This scene takes place "twenty years ago." Superman and Batman's ages for the past couple decades have rested somewhere in their late thirties or early forties. And, no, we're really not supposed to worry much when the numbers don't quite add up.
Update 2011: The timeline has been further complicated by DC's 2011 reboot. Batman and Superman are now quite a bit younger, yet Batwoman's history remains intact.
Update 2013: The Batwoman comic has proved one of DC's biggest successes in the "New 52" rebooted universe. However, the creative team announced in September 2013 they would leave the book, because DC refuses to allow Batwoman to marry her girlfriend, Maggie Sawyer, as the writer and artist had planned.
Update 2019: A CW Batwoman TV series premiered on October 7, 2019. It stays loosely faithful to the Kate Kane of the comics, though it changes elements of her origin, makes her a relative of Bruce Wayne, and has her inherit the Batcave after he goes missing.
Update 2020: Ruby Rose left the role behind, and the replacement Batwoman on the TV show has become an entirely different character.