A minor British king, Constantine likely succeeded his father as king of Dumnonia in 537. Reportedly married to the daughter of Brittany’s king, he lived a sinful life until he converted to Christianity by St. Petroc. After his wife’s death, he abdicated the throne and entered religious life. After founding churches in Cornwall and serving in monasteries in Wales and Ireland, he went as a missionary to the Picts in Scotland. He was abbot of Govan, before being killed by pirates. The biography of the man called Scotland’s first martyr is probably a conflation of the lives of several sixth–century Christians. His feast in Cornwall and Wales is March 9.