Warned of Chilperic’s playboy reputation, Athanagild had not immediately accepted Chilperic’s offer of marriage. Brunhild had converted from Arianism to Catholicism for Sigibert. Galswintha would also convert to her new husband’s preferred religion, but only on the condition that Chilperic be her faithful Christian husband. The Visigoths were much more prudish in this respect; their code prohibited the keeping of concubines and mistresses. And so Athanagild demanded Chilperic swear a solemn oath, a sacramentum, to repudiate all other women. Everyone would have understood who, exactly, Athanagild was referring to. This was the precondition to the marriage that Chilperic so eagerly sought: a king must swear to stay away from a slave. The fact that Chilperic was forced to make this particular promise hints that Fredegund’s hold over the king had already raised some eyebrows. There seems to have been no concern that his exiled first wife might return from her cloister – even though her three legitimate sons were being groomed to be warriors in their father’s armies – nor that any other of Chilperic’s former mistresses would dare disrespect this new powerful queen. But Fredegund, specifically, was perceived to be a potential problem. Chilperic agreed to this demand. He wanted this illustrious alliance more than he wanted any slave girl. He readily agreed that Fredegund would be sent away. But she would not be cast aside so easily. She kept her own counsel – and made her own plans.
Shelley Puhak, The Dark Queens: A gripping tale of power, ambition and murderous rivalry in early medieval