He established a monastery and school in the area now known as Rosscarbery towards the end of the sixth century. It flourished for three hundred years and survived in some form until the coming of the Normans to Ireland. It was the centre from which the
Diocese of Ross developed. Fachtna, born at a place called Tulachteann, was one of the pupils of
Saint Ita. In some Latin documents, he is called Fachtna Facundus (Fachtna the Eloquent) and even spoken of as Sanctus Facundus. In Irish records, he is generally referred to as Mac Mongach (Hairy Child), because he was reported to have been born with his head covered with hair. The interpretation of this phrase by
James Ussher and others as meaning Son of Mongach was rejected by
Mervyn Archdall. ==Veneration==