What is "charivius"

Charivius or Hervé was a Frankish dux Cenomannicus or Duke of Maine in the early eighth century. In 723 he seized the revenues of the Diocese of Le Mans. On the death of the bishop Herlemund he took control of the see and its monasteries and appointed his illiteratre son Gauciolenus bishop. Though the date of Charivius' death is unknown, his son retained control of the diocese and the region as bishop until 771.