“Though St. Nathy has always enjoyed as high a reputation for sanctity as any saint in the Irish church, there is little known his life, and hardly anything about his earlier years. Irish hagiologists, when the name occurs, speak of our saint in terms of the greatest respect, as most holy (sanctissimus), as of exquisite sanctity (sanctimoniae spectatissimae), ... , but still none of them gives a formal account of his life, or even mentions incidentally such facts as would throw much light on his career.” (O’Rorke)
Collooney Church Window
It is generally accepted that Nathy was born in Sligo, possibly of the O’Hara family, that he was a student of St. Finian at Clonard, and that later he and Finian founded a church and monastery at Achonry. This monastery became a school of piety and learning. We are told in tradition that Nathy taught several eminent men there. The most famous disciple of the school at Achonry was St. Fechin.
Nathy is commonly referred to in the writings as Crumther Nathy or Cromnathy (Irish Cruimhthir, a priest). This raises the question of whether Nathy was ever a bishop. There is no agreement on this point.
From the likelihood that Nathy had been a priest for some years when St. Finian died in 552 and that he was still alive when St. Fechin founded the abbey in Fore - which was probably not before 610 - O’Rorke argues that St. Nathy must have lived not less than 90 years. (In this longevity he prefigured a later Bishop of Achonry, Bishop Eugene (Owen) O’Hart, who was one of the three Irish bishops to attend the Council of Trent and who died in 1603 in the hundredth year of his age.)
In summing up St. Nathy’s life O’Rorke says:
”The impression ... which his works produced on the minds of his contemporaries has been handed down in the tribute which the successive writers that mention the name of Nathy never fail to pay to his extraordinary sanctity. Other Irish saints are noted for characteristic virtues: Columbkille, for love of churches; Finian of Clonard, for zeal in teaching; Brendan for pious voyages; Columbanus and others, for missionary activity; but the patron of Achonry shines chiefly by preeminent sanctity. It is a great distinction.”