Comprises portions of Galway, Roscommon, and Offaly counties; suffragan of Tuam; founded, 557, by Saint Brendan the Navigator. A famous school developed around the monastery which he established there. The west doorway and east windows of the old cathedral, used by the Protestants since the Reformation, are noteworthy specimens of the Irish Romanesque style. Bishops of the diocese include Cummian Fada, whose learned "Paschal Epistle" is of importance, and Jolin, an Italian prelate who beautified the cathedral (13th century). See also the patron saints index.