Erzsébet Báthory
Countess Elizabeth Báthory (Erzsébet Báthory) (1560 –1614) was a Hungarian noblewoman. She has been labeled as the most prolific female serial killer in history (documented, at least). She was accused at trial of torturing and murdering hundreds of young girls & women between 1590 and 1610. The stories of her sadistic murders were verified by the testimony of more than 300 witnesses and survivors, as well as many bodies. Eyewitnesses reported seeing her carrying out severe beatings, mutilation, burning, freezing, and starving girls to death. Because of her family’s status, she was not executed but rather imprisoned for the remainder of her life in Cachtice Castle. Folklore (although unsubstantiated) about Báthory has followed her throughout history, saying she bathed in the blood of virgins. Her legacy certainly lives on in modern popular culture.
Good news is, Queen Mary herself was dead 4 years later at age 42.
Karma's a b*tch.
Hmm, I'm thinking Arsenio Hall.