Wiki information Catharnach:

Fearghal mac Catharnach
Man, Person

Fearghal mac Catharnach, Lord of Loch Riach, died 821/823. Fearghal was ruler of Loch Riach in what is now County Galway. He appears to have been a son of Cathrannach mac Cathal, described as of Maenmag in the Annals of Ulster upon his death in...