Harristown was a part of the demesne of Castlemartin House and Estate owned by the (Fitz) Eustace family, namesakes of nearby Ballymore Eustace.[3] Harristown Castle on the border of the Pale was fortified in the 15th century by Rowland FitzEustace, 1st Baron Portlester.[5] In the 17th century Harristown House was built near the castle by the Lord Chancellor of Ireland, Sir Maurice Eustace. In 1684 (regnal year 33),[6] Sir Maurice Eustace obtained a royal charter from Charles II incorporating Harristown as a borough.[2][4] The borough was a rotten borough with "not one house and but one tree inhabiting".[6] Its boundaries encompassed 100 acres[2][4] whereas the townland as a whole had 618 acres (250 ha). The 1684 charter also established a manor of Harristown, with a court leet, court baron and court of record for 4,000 acres (1,600 ha) of land in the townlands of Harristown, Dunstown, Carnalway, Milltown and others.[2][4] After Maurice Eustace's death with no son, his estate was divided between three daughters, corresponding to Harristown, Mullacash and Carnalway, the first of which fell to the eldest daughter, Anne.[7]
Anne's son Eustace Chetwood[8] sold the estate to James FitzGerald, 1st Duke of Leinster, and his son William resold it to David La Touche, whose son John took up residence in 1783 in the new Harristown House, designed by Whitmore Davis.[2][3][9] Authorised by an Act of the Parliament of Ireland, La Touche enclosed the grounds of the house, building the "New Bridge" over the Liffey to carry the redirected Naas–Dunlavin road[9] (now the R412). Once the borough was disenfranchised by the Act of Union, the corporate officers, who had no functions other than for parliament, were discontinued.[4] The Corporation Book covering 1781 to 1800 is in the National Library of Ireland.[10] In 1906 the Corporation Book from 1714 was in the library of Maurice FitzGerald, 6th Duke of Leinster at Carton House.[9]
^ abcdef"Harristown". The Parliamentary Gazetteer of Ireland: Adapted to the New Poor-law, Franchise, Municipal and Ecclesiastical Arrangements, and Compiled with a Special Reference to the Lines of Railroad and Canal Communication, as Existing in 1844–45. Vol. II: D-M. A. Fullarton and Company. 1846. p. 295.
^ abcdeBaldwin, Henry (1835). "Harristown". In Royal Commission appointed to inquire into the municipal corporations in Ireland (ed.). First report; Appendix, Part I. Command papers. Vol. [23] 27 1. London: HMSO. p. 178.
^Lyons, Mary Ann (2000). Church and Society in County Kildare, 1480-1547. Four Courts Press. p. 152. ISBN9781851824595.
^ ab"Constituencies: Harristown". History of the Irish Parliament. Ulster Historical Foundation. Retrieved 1 August 2013.