Slave attendant turned queen, Fredegund (c. 550-597) cleared the way for her son to rule a reunited Francia by her ruthless use of assassination as a political tool.

Among the enslaved women who attracted the attention of Merovingian monarchs while serving in the royal households, Fredegund was among the small number who became queens, not merely concubines. She survived political dangers which would have ended the careers of even wellborn queens and retained her husband's loyalty though unable to provide him with healthy sons. Developing innovative methods of assassination and the ability to persuade others--even monks and priests--to join her plots, Fredegund distinguished herself by sheer viciousness. By the standards of her day, she was a great success: she was honored by her royal husband, accumulated a great treasure chest, put her son on his throne, and even died a natural death.

It is impossible to recover any...