Fedelmid mac Crimthainn was the King of Munster between 820 and 846. He was numbered as a member of the Céli Dé, an abbot of Cork Abbey and Clonfert Abbey, and possibly a bishop. After his death, he was later considered a saint in some martyrologies.
Read more about Fedelmid Mac Crimthainn: Early Kingship, High Point of His Rule, Downfall, Death, Annalistic References