This biography explores the life of the 16th-century "Blood Countess" of Hungary, Erzsébet Báthory. Reputed to be both a vampire and the world's worst female serial killer, she allegedly bathed in the blood of her 650 victims. Based on newly-found source material, translated into English for the first time, this book explores the actual life and trial of Countess Báthory, through letters, documents, and trial transcripts.