Gregory of Tours accused Mummolus of subjecting many Franks who had hitherto been free of taxation. During his wars against Chilperic, Mummolus had obtained the enmity of his queen Fredegunda, who accused him of responsibility for the death of her son Theodoric and of practising sorcery.
Gregory of Tours criticized Mummolus for imposing new taxes on many Franks who had been previously tax-free. During his wars against Chilperic, Mummolus antagonized Queen Fredegunda, who held him responsible for the death of her son Theodoric and accused him of using dark arts.