The vernacular Life of St Berach, Betha Beraigh, is concerned with the reputed founder of the church of Clúain Coirpthe, modern Kilbarry (Cell Beraig, ‘Berach's church’, parish of Termonbarry, County Roscommon, province of Connacht). The only other Life extant is the Latin Vita Sancti Berachi. Since the two Lives and a few genealogies are the only documents available about Berach, and since this saint is not mentioned in the annals, the historicity of Berach cannot be established. His proposed floruit may be estimated from the other persons he is brought into contact with within the text of his Irish Life. Judging by the mention of meetings with Colum Cille (St Columba) and the prophecy of St Patrick made sixty years before the birth of Berach, the saint is supposed to have lived in the sixth century.

Both Latin and Irish versions are rather late and give no evidence of having been based on any earlier texts. The Irish Life of Berach is found solely in Brussels MS 4190–4200 (3409), ff. 71–88 in the Bibliothèque Royale at Brussels, and the text itself is ‘much fuller and more original’ than the Latin version. MS 4190–4200 contains hagiographical and other religious literature in Irish and Latin, and is part of a collection made in Ireland by Míchél Ó Cléirigh in the second quarter of the seventeenth century.