The Conolly archive, which is now dispersed among a number of mainly institutional locations in Ireland, comprises c. 15,000 letters and papers ranging in date from 1570 to 1953. It derives from the Conolly family of Castletown, Co. Kildare, and mainly relates to William Conolly (1662–1729), Speaker of the Irish House of Commons (1715–29), generally considered to be the richest man in Ireland (and possibly the ablest), to his nephew William Conolly Junior (1706–54) and to his great-nephew, Thomas Conolly (1738–1803). The archives are deposited in the National Library of Ireland, Trinity College Dublin, the Public Record Office of Northern Ireland, the National Archives of Ireland and the Irish Architectural Archive; some are also in private hands. This calendar provides summaries of the papers in all of these archives while those in the NLI and are here made available for the first time. There is material here of national interest but also papers relating to estates in counties Kildare, Leitrim, Offaly, Meath, Westmeath, Roscommon, Donegal, Fermanagh, Wexford, Waterford, Dublin and Derry as well as estates in England and Wales. The famous Lennox sisters, the Dukes of Leinster, Lord Edward FitzGerald and many others make appearances.