Countess Elizabeth Báthory de Ecsed was a Hungarian noblewoman and allegedly serial killer from the family of Báthory, who owned land in the Kingdom of Hungary.
Báthory has been labeled by Guinness World Records as the most prolific female murderer, though the number of her victims is debated. Báthory and four collaborators were accused of torturing and killing hundreds of girls and women between 1590 and 1610. The highest number of victims cited during Báthory's trial was 650 but this number comes from the claim by a servant girl named Susannah that Jakab Szilvássy, Báthory's court official, had seen the figure in one of Báthory's private books. The book was never revealed and Szilvássy never mentioned it in his testimony. Despite the evidence against Báthory, her family's importance protected her from a death sentence. She was imprisoned in December 1610 within Castle of Csejte, in present day Slovakia.
The stories of Báthory's sadistic serial murders are verified by the testimony of more than 300 witnesses and survivors as well as physical evidence and the presence of horribly mutilated dead, dying and imprisoned girls found at the time of her arrest.