PARSONSTOWN, formerly Birr, a market-town of King’s County, Ireland, is situated on an acclivity rising above the Birr, and on a branch of the Great Southern and Western Railway, 12 j miles north of Roscrea and 7j south of Banagher. Cumberland Square, in which there is a Doric column, surmounted by a statue of the duke of Cumberland to commemorate the battle of Culloden, contains a number of good shops, and the streets diverging from it are wide and well built. The fine castle of Birr, besides its historical interest, has gained celebrity on account of the reflecting telescope erected there (1828-45) by the third earl of Rosse. The other principal buildings are the court-house, the Protestant Episcopal and Roman Catholic churches, the convent of the sisters of mercy, the model school, the mechanics’ institute, the fever hospital, and the infirmary. There is a bronze statue by Foley of the late Lord Rosse. Some trade is carried on in corn and timber, and the town possesses a distillery and brewery. The population was 5401 in 1861, 4939 in 1871, and 4955 in 1881.

An abbey was founded at Birr by St Brendan. The district formed part of Ely O’Carrol, and was not included in King’s County till the time of James I. A great battle is said to have been fought near Birr in the 3d century between Cormac, son of Cond of the Hundred Battles, and the people of Munster. The castle was the chief seat of the O’Carrols. In the reign of James I. it and its appendages were assigned to Lawrence Parsons, brother of Sir William Parsons, surveyor-general. It was more than once besieged in the time of Cromwell, and was taken by Ireton in 1650. It also suffered assault in 1688 and 1690.