ARMAGH, an inland county of Northern Ireland (Act of 1920), bounded north by Lough Neagh, east by County Down, south by Louth, and west by Monaghan and Tyrone. The area is or about 512sq.m. Pop. 110,070. The northern low lying area is made up of Tertiary basalts, Pliocene deposits and sandstones. It is very fertile and may formerly have been cov ered by the waters of Lough Neagh. To the south there is a gradual rise to the mountains of Ordovician and Silurian rocks, probably extensions of similar formations in the southern uplands of Scotland. Farther south, the granite mountain-core is revealed, whilst younger intrusive rocks form Slieve Gullion (1,893ft.). Historical Survey.—During early neolithic times lakes and swamps covered large portions of the lowlands of Ulster, the drier districts being thickly wooded. The first settlements were, therefore, largely confined to the coasts. In the bronze age col onization of the lowlands developed, and at its end the country immediately south of Lough Neagh had considerable importance. The fortress of Emhain Macha was built c.3oo B.C. about 11m. W. of the modern city of Armagh and became in time the re ligious and political centre of the district. Later, however, iron using people moved northward and drove some of the previous inhabitants of North Armagh into the mountains of county Antrim and county Down. To consolidate their conquests, they built an earth-work, erroneously known as the Dane's Cast, which follows approximately the modern boundary between county Ar magh and county Down. From this time Emhain Macha declined, the later associations of the district being woven around Armagh (q.v.) near by, which became in the fifth century the ecclesiasti cal capital of Ireland, partly because of its connections with St. Patrick. Scandinavians sailed up the Bann and established a per manent fleet on Lough Neagh. They also had squadrons on the loughs of Belfast, Strangford and Carlingford. From these cen tres they raided the interior and during one such expedition they destroyed Armagh but, recognizing the advantages of the site, used it for several years as the Scandinavian capital of North Ireland.
The Normans experienced great difficulties when moving against the North and kept to coastal routes and lowlands. They thus had comparatively little influence in Armagh, particularly in the southern hilly portion. The county was made shire ground in 1586.
The chief towns are in the northern lowlands. Armagh (q.v.), with its religious associations, is a route centre and market town. Both Lurgan and Portadown have considerable manufactures, chiefly connected with linen. The latter is also an important rail way centre. The county is poor in minerals though lead veins have been worked spasmodically. There are extensive granite quarries at Bessbrook. The scattered nature of the population of the mountains is shown by the fact that the railways enclose the area but send off no important branches. Along the east of the mountains is the line from Armagh to Newry and Carlingford; on the west, the line from Armagh to Castleblayney and Dundalk.
The county is divided into five urban districts, three rural dis tricts and two Poor Law unions. It returns four members to the parliament of Northern Ireland and one member to the parlia ment of Great Britain and Northern Ireland.