[citation needed] W. H. Grattan Flood, author of the History of the Diocese of Ferns,[4] illustrates the origin of the Diocese, by stating: It is a far cry back to the year 598, when the See of Ferns was established, with St. Aedan (Mo-Aedh-og or Mogue) as first Bishop.

St. Aedan died on January 31, 630, leaving a fragrant memory behind him, and his episcopal See was known as Fearna-mor-Moedhoc.

"[5]The following is a list of the most recent post-Reformation Roman Catholic bishops and vicars apostolic.

[6][7] The October 2005 Report of the Ferns Inquiry has outlined the serious levels of clerical sex abuse in the diocese since the 1960s.

It strongly criticised the former bishops of Ferns, Donal Herlihy and Brendan Comiskey for their inability to deal with the allegations of sexual abuse made against a number of priests.