Bron was bishop of Caisel-irrae, in Ui-Fiachrach-Muaidhe. Dr. Kelly (Cal. Ir. SS. 4) identifies his see as Kilasbuigbrone, near Sligo, in Ireland. In Colgan he is "Episc. Bronus filius ignis, qui est in Caisselirra, servus Dei, socius Sti. Patricii," but he call give no account of his receiving from Evinus the designation filius ignis, except that his father's name may have been Aidh (fire). The Four Masters give his death as having occurred June 8, 511, and to this O'Donovan adds a note on Cuil-irra, and traces, from the Annotation of Tirechan and the Book of Armagh, the wanderings of St. Patrick, till "crossing the Muaidh (Moy) at Bertriga, (Bartragh), he raised a cross there, and proceeded thence to the mound of Riabart,lnear which he built a church for his disciple, bishop Bronus, the son of Icnus." This is called the church of Casselirra in the Trip. Life of St. Patrick.