She was considered the first most infamous Vampire in myth and legend  and was labeled the Queen of Blood because of  her horrific sadistic scrims he commited in her lifetime.
She was of noble birth and at the time her family was considered one of the most powerful  families in Transylvania. Even though she married she had a great many lovers.
At a certain point in time she began to be terrified at the prospect of growing old and losing her  beauty, so after the death of her father she decided to move to Vienna this was when she began to dabble in the occult. This involved vicious rituals involving bloody sacrifices of animals.
Her obsession was at first quite harmless, but her fascination in blood grew, her conviction grew to such extremes she believed that there was a connection between the secret of eternal youth and beauty and the blood of young girls. To all counts she murdered 600 woman in her bid to attain eternal youth. She took great care in murdering each and every victim, they had to die a slow agonizing death, in some cases it took victims months to die. She would cage them and would antagonize her victims wounding them with burning irons, sometimes she would hang the cage from the ceiling and then wound the victim so severely so that she then could take a bloody shower drenching herself in their blood. Even being of nobility did not grant her immunity, questions began to be raised finally in 1610 she was brought to trial for the deeds she had done. The trial had been arranged so quickly not for the justice for the murdered victims but the government wanted to confiscate and control all her belongings and land she owned.
During the trial no one could believe that she had killed so many woman by herself so she had to have an accomplice After thorough investigation her accomplices were found and duly put to trial, and the brains behind the finding of victims for Bathory as well as the disposal of the bodies and evidence Erzsi Majorova was convicted and put to death.

Because she was of nobility she could not be sentenced to death, she was therefore sentenced to life imprisonment in her own castle in Catchice. She did not have the run of the castle because she was placed in a small room which was completely bricked in so she had no contact with the outside world. There was only a small opening to allow food to be passed to her, and a few ventilation slits. She died alone in the room in 1614.
Even after her death her reputation grew, especially her greed for blood in her attempts to attain eternal youth.