Today (14 August) we commemorate St. Fachanan (Fachtna), abbot of Ross Carbery (ca. 600). Not to be confused with St Fachanan of Kilfenora. Baring-Gould is brief:
S. FACHTNA, or Fachnan, of Ross, was a bishop living at Rosscarberry, about 570. He is said to have been a disciple of S. Finlass of Cork, but this is a mistake, for he was prior to him. He was for some time, and to all appearance before he settled at Ross, Abbot of Darinis Moelanfaidh, new Molana, a small island of the river Blackwater in the county of Waterford. His school at Ross was one of the most celebrated and frequented in Ireland, and continued so after his death. He was for some time blind.
Catholic Encyclopedia on the School of Ross
celt-saints has an unusually long entry, quoting and citing this article from the Irish Ecclesiastical Record, and also Under the Oak, which quotes this article from another number of the Irish Ecclesiastical Record.
Holy St Fachtna, pray to God for us.