While pursuing new assignments at DC Comics' offices in New York City, Karl Kesel was approached by former DC editor Matt Idelson to create a pitch for Harley Quinn's first ongoing series, which Karl accepted, being a fan of the character after having read Dini's Mad Love.

[1] Kesel's run on the series began being published in December 2000, and was about Harley Quinn leaving the Joker and becoming a solo criminal, alongside a supporting cast of henchmen named the Quinntets.

[1] Because of underwhelming sales, his 25-issue run ended in December 2002, and DC decided to change the creative team; the series was given to writer A.J.

Lieberman and artists Mike Huddleston and Troy Nixey by Idelson, and took on a grittier and darker direction, contrasting Kesel's run.

[4][5] Harley Quinn's relaunched ongoing series is a direct continuation of the former, with Conner and Palmiotti still writing for the character, and Hardin and Timms illustrating the interior art.