PORTARLINGTON, a market town situated partly in King's county but chiefly in Queen's county, Ireland, on both banks of the river Barrow, here the county boundary. Pop, (1901), 1943. The railway station, a mile south of the town, is an important junction, 42 m. west by south from Dublin, of the Great Southern & Western system, where the branch line to Athlone leaves the main line. Monthly fairs are held, and there is considerable local trade. After the revocation of the edict of Nantes a colony of French refugees was established here in the reign of William III., and the beautiful church of St Paul (rebuilt in 1857) was devoted to their use, services being conducted in the French language, for which reason the church is still spoken of as the “ French Church.” The former name of the town was Cooltetoodera, but on the property passing into the hands of Lord Arlington in the reign of Charles II. the name was changed. Emo Park, 5 m. south of the town, is the fine demesne of the earls of Portarlington, a title granted to the family of Dawson in 1785. An obelisk on Spire Hill near the town is one of the many famine relief works in Ireland. On the river, close to the town, there are picturesque remains of Lea Castle, originally built c. 1260. Portarlington was incorporated in 1667, and was a parliamentary borough both before the Union and after, its representation in the imperial parliament (by one member) being merged in that of the county by the Redistribution Act of 1885.