ROSCOMMON, a market town and the county town of Co. Roscommon, Ireland, situated on rising ground in a bare plain in the centre of the county, on the Mayo line of the Midland Great Western railway, 18¼ m. N.W. by N. from Athlone. Pop. (1901) 1891. It contains the county buildings, and has Protestant and Roman Catholic churches, the latter of which is a ine building completed in 1903. An extensive trade is carried on in agricultural produce and live stock. A castle, dating from 1268, when it was founded by John d'Ufford, justiciary of Ireland, stands, an imposing mass of ruins, but far gone in decay, overlooking the plain. It fell to besiegers in 1566, 1642 and 1652, and was partially burned after the battle of Aughrim in 1691. There are also remains of a Dominican priory of the middle of the 13th century, founded by Felim O'Conor, king of Connaught, and exhibiting fine, though mutilated, details of the style of that period. The name of the town, signifying St Coman's wood, is derived from the saint who founded the monastery of Canons Regular here in the 6th century. The town received charters from Edward I. and James I. Two m. N.E. are small remains of the abbey of Deerane.