Saint Celsus, bishop of Armagh

Saint Celsus, bishop of Armagh, was one of the most prominent Irish prelates of the 11th and 12th centuries. Born in 1080, he became Bishop of Armagh in 1105 and worked tirelessly to reform the Irish church and promote ecclesiastical discipline. Celsus was noted for his holiness, wisdom, and efforts to end hereditary succession in Irish dioceses. He died in 1129 and is venerated for his significant contributions to the Church in Ireland.