Elizabeth Báthory Countess Elizabeth Báthory de Ecsed (Báthory Erzsébet in Hungarian, Alžbeta Bátoriová in Slovak; 7 August 1560 – 21 August 1614) was a countess from the renowned Báthory family of nobility in the Kingdom of Hungary. She has been labelled the most prolific female serial killer in history and is remembered as the "Blood Countess," though the precise number of victims is debated. Since her story comes only from those who accused her and was only written down more than 100 years after her death, it quickly rose to folkloric and horrific proportions.
Source: Wikipedia