Custennin I of Cornwall (410-443) was the king of Cornwall from 435 to 443, succeeding Cynfawr of Cornwall and preceding Erbin of Cornwall.
Biography[]
Custennin was born in 410, the son of King Cynfawr of Cornwall, a monarch of the royal Christian Breton House of Dyfnaint. Custennin succeeded his father as king in 435, and he reigned for just eight years before dying at the age of thirty-three. His son Erbin of Cornwall succeeded him as king.