 Complete the following phrase:  At the beginning of the medieval era, Brittany was divided among three kingdoms, Domnonea, Cornouaille and Broërec. These realms eventually merged into a single state during the 9th century. The unification of Brittany was carried out by Nominoe, king between 845 and 851 and considered as the Breton Pater Patriae. His son Erispoe secured the independence of the new kingdom of Brittany and won the 