ROSCOMMON COUNTY, a county of Ireland in the province of Connaught, bounded N.E. by Leitrim, N.W. by Sligo, W. by Mayo, W. and S. by Galway, E. by Longford and E. and S. by Westmeath and King's County. The area is 629, 633 acres, or about 985 sq. m. The greater part of the county belongs to the great limestone plain of central Ireland, and is either flat or very slightly undulating. In the north-east, on the Leitrim border, the Braulieve Mountains, consisting of rugged and precipitous ridges with flattened summits, attain an elevation in Cashel Mountain of 1377 ft.; and in the north-west the Curlew Mountains, of similar formation, between Roscommon and Sligo, rise abruptly to a height over 800 ft. In the east the Slievebawn range, formed of sandstone, have a similar elevation. The Shannon with its expansions forms nearly the whole eastern boundary of the county, and on the west the Suck from Mayo forms for over 50 m. the boundary with Galway till it unites with the Shannon at Shannon Bridge. The other tributaries of the Shannon within the county are the Arigna, the Feorish and the Boyle. The lakes formed by expansions of the Shannon on the borders of Co. Roscommon are Loughs Allen, Boderg, Boffin, Forbes and Ree. Of the numerous other lakes within the county th'e most important are Lough Key in the north, very picturesquely situated with finely wooded banks, and Lough Gara (mostly in Co. Sligo) in the north-west.
In this long county one may travel fifty miles across the Carboniferous Limestone plain, with the grey rock cropping out here and there, and long grass-covered esker-ridges forming the only obstacle to the roads. Lough Ree is a typical lake of the plain. Two inliers of Silurian rocks have been thrust up, forming hills between Lough Ree and Lough Boffin. At Boyle, however, higher Old Red Sandstone country is encountered, and farther north the Millstone Grit and Coal-Measure series cap the mountains almost horizontally at Arigna near Lough Allen. The nodules of clay-ironstone here were formerly smelted, and the seams of bituminous coal, mostly on Millstone Grit horizons, are worked successfully on a high level of the mountains.
The subsoil is principally limestone, but there is some light, sandy soil in the south. In the level parts the land when drained and properly cultivated is very fertile, especially in the district known as the plains of Boyle, which includes some of the richest grazing land in Ireland. Along the banks of the Suck and Shannon there is, however, a large extent of bog and marsh. The proportion of tillage to pasture is roughly as one to three. Oats and potatoes are the principal crops, but the acreage devoted to them decreases; the numbers of cattle, sheep, pigs, goats and poultry, on the other hand, are proportionately large and increasing. Communications are afforded by the Midland Great Western railway, the Sligo line of that system crossing the northern part of the county by Boyle, the Athlone and Mayo line passing from S.E. to N.W. by the towns of Roscommon and Castlerea, and the Athlone and Galway line crossing the southern part.
The population was 116,552 in 1891, and 101,791 in 1901; 97% are Roman Catholics, and nearly the whole population is rural. The chief towns are Boyle, Roscommon, Elphin and Castlerea; and a small portion of Carrick-on-Shannon, including the railway station, is in this county, the major portion being in Co. Leitrim. The county is divided into ten baronies. Ecclesiastically it belongs to the Protestant dioceses of Elphin and Ardagh (united with Kilmore and Tuam), and to the Roman Catholic dioceses of Tuam, Clonfert, Achonry, Elphin and Ardagh. Assizes are held at Roscommon and quarter sessions at Boyle, Strokestown and Roscommon. The county returns two members to parliament. To the Irish parliament before the Union of 1800 two members were returned for the county, and two each for the boroughs of Boyle, Roscommon and Tulsk.
The district was granted by Henry III. to Richard de Burgo, but remained almost wholly in the possession of the native septs. Until the time of Elizabeth Connaught was included in the two districts of Roscommon and Clare, but in 1570 it was further subdivided by Sir Henry Sydney, and was assigned its present limits. All the old proprietors were dispossessed at the Cromwellian settlement, except the O'Conor family headed by the O'Conor Don. The most interesting antiquarian remains within the county are the ruins of Crogan, the ancient palace of the kings of Connaught. The principal ancient castles are the old stronghold of the M'Dermotts on Castle Island, Lough Key, the dismantled castle of the M'Donoughs at Ballinafad, and the extensive fortress at Roscommon rebuilt by John d'Ufford, justiciary of Ireland in 1268. There are fragments of a round tower at Oran. The abbey of Boyle is in remarkably good preservation, and exhibits fine specimens of the Norman arch. The other monastic remains within the county, with the exception of the abbey of Roscommon, are of comparatively small importance. The Irish bard Carolan, who died in 1738, is buried by the ruined church of Kilronan, in the extreme north of the county. The bishopric of Elphin was united with Kilmore and Ardagh in 1833, and the former cathedral and episcopal buildings are largely modernized.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)