Countess Elizabeth Báthory de Ecsed (7 August 1560 – 21 August 1614) was a countess from the renowned Báthory family of nobility in the Kingdom of Hungary. She has been labeled the most prolific female serial killer in history, although the number of murders is debated, and is remembered as the "Blood Countess."
After her husband Ferenc Nádasdy's death, she and four collaborators were accused of torturing and killing hundreds of girls, with one witness attributing to them over 650 victims, though the number for which they were convicted was 80. Elizabeth herself was neither tried nor convicted. In 1610, she was imprisoned in the Csejte Castle, now in Slovakia and known as Čachtice, where she remained bricked in a set of rooms until her death four years later.
Later writings about the case have led to legendary accounts of the Countess bathing in the blood of virgins to retain her youth and subsequently also to comparisons with Vlad III the Impaler of Wallachia, on whom the fictional Count Dracula is partly based, and to modern nicknames of the Blood Countess and Countess Dracula.