Causantín mac Fergusa

Causantín or Constantín mac Fergusa (English: "Constantine son of Fergus") (789–820) was king of the Picts, in modern Scotland, from 789 until 820. He was until the Victorian era sometimes counted as Constantine I of Scotland; the title is now generally given to Causantín mac Cináeda. He is credited with having founded the church at Dunkeld which later received relics of St Columba from Iona.