August 1614: the notorious 54-year-old royal died under house arrest in Čachtice Castle in modern-day Slovakia, having been implicated in as many as 650 deaths — mostly peasant girls and servants. Her identity: Erzsébet “Elizabeth” Báthory, a late-16th-century Hungarian countess.
The most prolific female serial killer known in history. All of the murders involved extreme torture. All were done largely for fun. Some think that she served as the template fro Bram Stoker's Dracula, given that she bit off pieces of her victims' faces and shoulders.