Dumnonii

The Dumnonier (Latin Dumnonii ) were a Celtic tribe that settled in the southwest of Britain (now Cornwall and Devon ). The first mention comes from the Greek traveler Pytheas in the 4th century BC, the most important city and the suburb Dumnonier their civitas after the Roman conquest in the 1st century AD was Dumnoniorum Isca (Exeter).

After the Roman withdrawal from Britain during the 4th and 5th century, a Celtic Kingdom of Dumnonia, from which populated the Dumnonier parts of Brittany was born.

The trunk is eponymous for the name of the county of Devon and notified thereafter geological formation.