Before the CRISIS Batwoman began her life as circus
perfomer Kathy Kane. A trapeze artist and stunt cyclist
for the circus, Kathy Kane realized she wanted more out
of life. Kane's admiration for The Batman led to her own
aspirations of becoming a crime-fighter. When Kathy gained
a considerable inheritance, she used it to acquire the supplies
she needed to fight crime. She had a mansion constructed
just above an abondoned mine tunnel, which became her
version of the Batcave, and filled the mine with her own crime-
laboratory. She constructed her own Bat-cycle. Like Batman,
Kathy created a number of weapons and crime-fighting
equipment. A lot of Kane's gadgets were kept in a utility purse,
which matched her version of the Cape Crusader's costume.
So began Kathy Kane costume identity as Batwoman.
Note: In the beginning it was spelled "Bat-Woman".

[ Detective Comics #233 ]

Batwoman would fight along side Batman and Robin
on numberous occassions. Batman would often try to
convince Kathy to quit her Batwoman alter-ego,
implying fighting crime was too dangerous for her.
Batwoman would prove him wrong as time passed.
Like Batman, Kathy Kane would gain a partner in
the form of her niece Betty Kane. During a visit to
her aunt's house, Betty discovered Kathy's costume
identity as Batwoman. Betty decided to follow her
aunt's idea and created her own crime-fighting identity
that of Bat-Girl. Both heroines proved to be romantic
foils for the Dynamic Dou.

Batwoman and Bat-Girl later retired from crime-fighting.
Kathy Kane bought a circus calling it Kane's Kolossal
Karnival. However, Kathy found herself becoming
Batwoman on occassions when needed, even teaming up
with another Batgirl (Barbara Gordon). It was not long
after, that Batman followed a tip that suggested the
League of Assassins were going after Kathy at her circus.
There Batman was knocked unconscious by the Bronze Tiger,
who was a thrall of the Sensei, leader of the League of
Assassins. When Batman awoke he found Kathy Kane
murdered by two members of the League. Batman later
tracked the two killers to the Sensei's lair, captured
them and avenged Kathy Kane's death.

[ Detective Comics #485 ]

Due to Crisis on Infinite Earths the crime-fighting
heroione known as Batwoman now never existed.
However, the existence of Kathy Kane is still
rather a mystery. Sucide Squad #38 reveals that
the Bronze Tiger played a hand in the murder of
"an old friend of Batman's--carnival owner
Kathy Kane." This seems keeping with the pre-crisis
history. Then in Beast Boy #3 Flamebird (Bette Kane)
mentions she has an aunt Kathy. This leads us to believe
that Kathy Kane might still be alive or this "aunt Kathy"
is someone else entirely. I guess time will tell.