Cyclopedia of Biblical, Theological and Ecclesiastical Literature
bishop of Inbher Daoile, now Ennereilly, in the barony of Arklow, County Wicklow, was the son of Colman, of the race of Labhraidh Lorc. His three brothers were saints, and he was progenitor of the men of Leinster. He was educated at Liathmore, under St. Mochoemoc or Pulcherius, and after visiting Rome became abbot of Inbher Daoile. He was a leader in the Paschal controversy, and although mentioned as intractable, is said to have been of a peculiarly mild disposition. He is perhaps the same as Dagamus (q.v.). He was born between 565 and 570, and died September 13, 641. Both March 12 and September 13 are given as his festival.
These files are public domain.
McClintock, John. Strong, James. Entry for 'Dagan (2)'. Cyclopedia of Biblical, Theological and Ecclesiastical Literature. https://www.studylight.org/encyclopedias/eng/tce/d/dagan-2.html. Harper & Brothers. New York. 1870.