Constantine of Cornwall (c.435 - c.443)

Constantine was a king of Dumnonia in the early fifth century. A later king of the same name also ruled Dumnonia in the mid-fifth century and picking the two lives apart has led to a great deal of uncertainty and confusion in the sources. How a king of Dumnonia gained a Cornish epithet is unclear. It may suggest that the royal family emerged from Cornwall or that Constantine was the man who brought Cornwall securely under the control of Dumnonia.

Born in c.411, Constantine succeeded his father, Conomor, in or around 435. From the few sources available, his reign appears to have been stable and uneventful. Dumnonia proved to be fiercely resistant to direct Roman rule and the Romans chose instead to manage it as a semi-independent province rather than occupy it militarily. Consequently, Dumnonia established itself as an independent kingdom with a strong and legitimate leader very soon after the Roman withdrawal. Also, being so far west, Dumnonia was not yet threatened by Saxon advances.

From the Welsh genealogies, Constantine appears to have had a brother, Dunstan, of whom very little is known and at least three sons. On his death in c.443, following Celtic tradition, his kingdom was divided between two of his sons. The eldest, Erbin, inherited the main kingdom of Dumnonia while his younger brother, Merion, ruled as a sub-king in Cornubia. The fate of the middle son, Digain, is unknown. Through Erbin, Constantine is recorded as the grandfather of Geraint, a later King of Dumnonia and an important character in Arthurian folklore.