Fredegund The Bloodthirsty
Fredegund (545 - 597 CE), the queen consort of Chilperic I - the Merovingian Frankish king of Soissons, has a reputation of being one of the most bloodthirsty and sadistic women in history. Accounts by Gregory, the Bishop of Tours (539 - 594 CE), depict her as a murderous woman who gained power by means of her husband and applied it to keep his kingdom in a state of war for more than forty years. She was also known as an early exponent of dirty warfare who relied heavily on poison and other covert operations.
However, this same lady also survived political intrigues and retained her husband's loyalty despite the fact that, for a long time, she was unable to provide him healthy sons. Fredegund also developed innovative methods of assassination and was evidently compelling enough to persuade even monks and priests to join her causes. She was honored by her husband, accumulated great fortunes, put her son on the throne, and died a natural death. After her death, her son later honored her by punishing her enemies.