Erispoe ( Herispogius, or Respogius; died 2 or 12 November 857) was Duke of Brittany from 851. After the death of his father Nominoe, he led a successful military campaign against the Franks, culminating in his victory at the Battle of Jengland. He is subsequently referred to as "King of Brittany", but this indicates only that he received a gift of regalia and not that he was ever king by imperial grant or even in his own charters. Erispoe's recorded titles include provinciæ Brittaniæ… (More on Erispoe)