CAVAN, a county in the province of Ulster, Ireland, bounded N. by Fermanagh and Monaghan, E. by Monaghan and Meath, S. by Meath, Westmeath and Longford, and W. by Longford and Leitrim. The area is 477,399 acres, or about 746 sq. m. The surface of the county is uneven, consisting of hill and dale, without any great extent of level ground, but only in its northern extremity attaining a mountainous elevation. The barony of Tullyhaw, bordering on Fermanagh, a wild dreary mountain district, known as the kingdom of Glan or Glengavlin, contains the highest land in the county, reaching 2188 ft. in Cuilcagh, the place of inauguration for the Maguires, chieftains of Fermanagh, held in veneration by the peasantry, in connexion with legends and ancient superstitions. The remainder of the county is not deficient in wood, and contains numerous lakes, generally of small dimensions, but of much beauty, especially Lough Oughter, with its many inlets and islands formed by the Erne river, between the towns of Cavan and Killashandra. The county also shares with other counties the waters of Lough Gowna and Lough Sheelin, in which, as elsewhere in the county, the fishing is good. The chief river in the county is the Erne, which originates in Lough Scrabby, one of the minor sheets of water communicating with Lough Gowna on the borders of Longford. The river takes a northerly direction by Killashandra and Belturbet, being enlarged during its course by the Annalee and other smaller streams, and finally enters Lough Erne near the northern limit of the county. The other waters, consisting of numerous lakes and their connecting streams, are mostly tributary to the Erne. A copious spring called the Shannon Pot, at the foot of the Cuilcagh Mountain, in the barony of Tullyhaw, is regarded as the source of the river Shannon. The Blackwater, a tributary of the Boyne, also rises in this county, near Bailieborough. Several mineral springs exist in this county, the chief of which is near the once frequented village of Swanlinbar. In the neighbourhood of Belturbet, near the small lake of Annagh, is a carbonated chalybeate spring. There are several other springs of less importance; and the small Lough Leighs, or Lough-an-Leighaghs, which signifies the healing lake, on the summit of a mountain between Bailieborough and Kingscourt, is celebrated for its antiscorbutic properties. The level of this lake never varies. It has no visible supply nor vent for its discharge; nor is it ever frozen during the severest winters.
Geology.—This elongated county includes on the north-west some of the highland of Millstone Grit and Coal-Measures that rises above Lough Allen. The beds below these are referred to the English Yoredale series, and include some flaggy sandstones. It is on this series that the Shannon rises, under the high outlier of grit on Cuilcagh. The Carboniferous Limestone then stretches down to Cavan town, a bold outlier of the higher strata being left above Ballyconnell. The river Erne forms, in the limestone area, a characteristic series of expansions and loops, with islands between them, known as Lough Oughter. At this point we pass on to the axis of underlying Silurian strata that runs from Longford to Donaghadee in Co. Down, and the country becomes hilly and irregular, culminating about Cross Keys on the old Dublin coach-road. A patch of granite, indicating doubtless a core like that exposed at Newry, is seen in a hollow at Crossdoney. On the south side of this axis of older rocks, we reach Carboniferous shale and limestone at Lough Sheelin, and here enter on the great central plain. The extreme south-east of the county includes part of the Triassic outlier of Kingscourt. The coal-seams and concretions of clay-ironstone in the north-west area resemble those mentioned under the head of Co. Roscommon. Anthracite, probably of inorganic origin, has been mined without permanent success in the Silurian beds near Kilnaleck, and is traceable freely, associated with veins of quartz and haematite, at Ballyjamesduff a little farther east.
Climate and Industries.—The climate suffers from the dampness arising from the numerous lakes and the nature of the soil, and from the boisterous winds which frequently prevail, more especially in the higher districts. The soil is generally a stiff clay, cold and watery, but capable of much improvement by drainage, for which its undulating surface affords facilities. Only about one-sixteenth of the total area is quite barren. Agriculture makes little progress; the extent of the farms being generally small. Oats and potatoes are the principal crops. Flax, once of some importance, is almost neglected. In the mountainous parts, however, where the land is chiefly under grazing, the farms are larger, and in stock-raising the county is progressing.
Cavan is not a manufacturing county. The bleaching of linen and the distillation of whisky are both carried on to a small extent, but the people are chiefly employed in agricultural pursuits and in the sale of home produce. The soil in those districts not well adapted for tillage is peculiarly favourable for trees. The woods were formerly very considerable, and the timber found in the bogs is of large dimensions; but plantations are now chiefly found in demesnes, where they are extensive.
The county is not well served by railways. The Great Northern from Clones to Cavan, and the Midland Great Western from Mullingar in Westmeath to Cavan, form a through line from north to south. The Great Northern has branches to Belturbet from Ballyhaise, and to Cootehill from Ballybay; the Midland Great Western has a branch to Killashandra, and from Navan in Meath to Kingscourt, just within Cavan. The Cavan & Leitrim railway starts from Belturbet and soon leaves the county to the west.
Population and Administration.—The population (111,917 in 1891; 97,541 in 1901), of which about 80% are Roman Catholics, shows a decrease among the most serious of the Irish counties, and emigration returns are among the heaviest. The population is almost wholly rural, the only towns being the small ones of Cavan (pop. 2822, the county town), Cootehill (1509), Belturbet (1587) and Bailieborough (1004). The county is divided into eight baronies, and contains thirty-two parishes and parts of parishes. It is almost entirely within the Protestant and Roman Catholic dioceses of Kilmore. The assizes are held at Cavan, and quarter sessions are held at Cavan, Bailieborough, Cootehill and Ballyconnell. Before the Union the county returned six members to the Irish parliament, two for the county at large, and two for each of the boroughs of Cavan and Belturbet; but since that period it has been represented in the imperial parliament by two members only, for the east and west divisions.
History and Antiquities.—At the period of the English settlement, and for some centuries afterwards, this district was known as the Brenny, being divided between the families of O'Rourke and O'Reilly; and its inhabitants, protected by the nature of the country, long maintained their independence. In 1579 Cavan was made shire ground as part of Connaught, and in 1584 it was formed into a county of Ulster by Sir John Perrott, and subdivided into seven baronies, two of which were assigned to Sir John O'Reilly and three to other members of the family; while the two remaining, possessed by the septs of Mackernon and Magauran, and situated in the mountains bordering on O'Rourke’s country, were left subject to their ancient tenures and the exactions of their Irish lord. The county subsequently came within the scheme for the plantation of Ulster under James I. The population is less mixed in race than in most parts of Ulster, being generally of Celtic extraction. Some few remains of antiquity remain in the shape of cairns, raths and the ruins of small castles, such as Cloughoughter Castle on an island (an ancient crannog) of Lough Oughter. Three miles from the town of Cavan is Kilmore, with its cathedral, a plain erection containing a Romanesque doorway brought from the abbey of Trinity Island, Lough Oughter. The bishopric dates from about 1450. A portion of a round tower is seen in the churchyard of the parish of Drumlane at Belturbet.