Harley Quinn was created by Bruce Timm and Paul Dini who are famous for producing the Warner Brothers' DC Comic Series. She first appeared in Batman: The Animated Series in an episode called Joker's Favor. Harley Quinn was originally intended to be a one shot character playing one of Joker's henchgirl. However with her spunky and naive personality which compliments her attractive appearance, she ended up becoming a big star of the series.
Harley Quinn’s history began when she was a working at Arkham Asylum, the place where criminals of Gotham City are sent. She was a psychiatrist with a bright future which she let go down the drain when she volunteered to have the Joker as her patient. She thought she was prepared for the assignment but instead became too sympathetic after listening to the Joker's so called “abusive childhood story”. The Joker ended up seducing her. Like putty in his hand, Harley fell hopelessly in love with Gotham's' most dangerous psychopath and she came to the conclusion that it was Batman who was the cause of the Joker's suffering and his path towards crime. One night after the Joker escaped Arkham, he returned in a physically damaged state after fighting with Batman which was the point at which Harleen snapped. With a clown costume and a supply of weaponry, Harleen broke Joker out of the asylum and became Harley Quinn. From that moment on, she became the pathetic lovesick henchgirl and basically Joker's doormat.
Her popularity grew so huge that she became an official character of the Batman Comics with the only difference from the television series being that in the comics she is a lot more deadly and less hilarious. Harley Quinn is a memorable character that makes you feel pity for her because of her love for the Joker; however, she has such a great personality that at times she can make you really laugh, as she says “Right-a-roonie!”
Here is a the full origin of Harley Quinn from Mad Love.
Here is a link to a clip on Youtube called Harlequinade:
All images are copyright and property of Warner Bros./DC Comics and Bruce Tim.