I. A county of northern Ireland, in the province of Ulster, between Lough Neagh on the north and the county of Louth on the south; area, 512 sq. m.; pop. in 1871, 171,355. In the S. W. part are several groups of inconsiderable mountains; the rest of the surface is level or undulating, and the soil is generally fertile. The principal rivers are the Black-water and the Bann. The northern and central portions of the county are divided into small farms; grain, vegetables, and flax are their products. Linen weaving is the chief manufacturing industry. The principal towns are Armagh and Newry; part of the latter lies also in the county of Down. Portadown and Lurgan are noted for their linen manufactures.

II. A city, capital of the preceding county, situated on the Callam, an affluent of the Black-water, 36 m. by railway W. S. W. of Belfast; pop. in 1871, 8,952. It is well built round a hill, from the centre of which rises the famous old cathedral, recently repaired and occupying the site of the original building erected by St. Patrick. The town is supplied with water from an adjoining reservoir and is lighted with gas. The Anglican and Roman Catholic archbishops of Armagh both bear the title of primate of all Ireland. The trade chiefly consists in grain, flax yarn, and linen. It lias several branch banks, and lively weekly corn and general markets, and the prosperity of the town is rapidly increasing. Between the 5th and 9th centuries Armagh was a renowned ecclesiastical and intellectual centre, and subsequently it was often devastated by the Danes. After the English invasion it was almost uninterruptedly under Irish rulers up to the reformation, after which period it became the scene of many conflicts between the English and Irish forces till the beginning of the 17th century.

The military headquarters, formerly in Armagh, have been removed to Belfast.