The Countess of The Blood: The Numbers

The Countess of the Blood was Elizabeth Bathory, and she lived in Transylvania after her marriage to a minor Hungarian nobleman.

Now according to 100 Tyrants she ordered (or aided) the murder of 600 village girls and minor noblewoman.  The reason she was not killed was due to the fact that the Bathory clan was a powerful clan and she was a member and the King of Hungary needed the support of the clan.