Helias was a native of what is now County Monaghan, apparently been a monk at the monastery of Muckno which is now the parish around the town of Castleblayney.
Trithemius states that he led "a most austere life, and was on that account an object of hatred to wicked men, who feared his reproof."
A French monk of St. Pantaleon having written, without permission, a neat copy of the Missal for the use of the community, Helias burned it, lest others should presume to act without previous licence.
He died in the odour of sanctity, and was buried in the chapel of St. Benedict, with the epitaph: Haec tumuli fossa conduntur Praesulis ossa/Heliae miri mirificique viri.
Jean Mabillon was of the opinion that he was the Stranger and Pilgrim to whom Berno of Reichenau dedicated The Laws of Symphony and Tone.