SNIPPET: In the 18th and 19th centuries the vast majority of the Irish population lived as small tenant-farmers on large estates owned for the most part by English or Anglo-Irish landlords, per genealogy expert John GRENHAM. The administration of these estates inevitably produced large quantities of records -- maps, tenant's lists, rental account books, lease books, etc. Over the course of the 20th century, as the estates were broken up and sold off, many collections of these records have found their way into public repositories, and constitute a largely unexplored source of genealogical information. There are, however, good reasons for their being unexplored. First, it was quite rare for a large landowner to have individual rental or lease agreements with the huge numbers of small tenants on his land. Instead, he would let a significant area to a middleman, who would then sublet to others, who might in turn rent out parts to the smallest tenants 'at will.' A related problem is the question of access. The estate records in the two major Dublin repositories (the National Archives and the National Library) are not catalogued in detail. The only comprehensive guide is given in Richard HAYES' "Manuscript Sources for the Study of Irish Civilization" and its supplements, copies of which can be found in the National Library and the National Archives. This catalogues the records by landlord's name and by county, with entries such as 'NL MS. 3185. Rent Roll of Lord CREMORNE's estate in Co. Armagh, 1797.' HAYES gives no further details of the areas of the county covered, and it can be difficult to ascertain from the Tithe Books or Griffith's Valuation just who the landlord was; Griffith's only supplies the name of the immediate lessor. The holdings in the Public Record Office of Northern Ireland present similar problems, with access depending on a knowledge of the landlord's name. Additionally, many of the collections in the National! Li! brary have still not be catalogued at all, and thus remain completely inaccessible. The largest single collection in the National Archives is the Landed Estate Court records, also known as the Encumbered Estate Courts, which are not catalogued in HAYES. The court was set up to facilitate the sale of estates whose owners could not invest enough to make them productive, and between 1849 and 1857 oversaw the sale of more than 3,000 Irish estates. Its records contain many rentals and maps drawn up for the sale, but are so close in time to Griffith's as to make them of limited use except in very particular circumstances. Once again, the principal problem of access is in identifying the relevant landlord, since they too are catalogued by the landlord's name. There are a number of ways to overcome, or partially overcome, this obstacle. It is often possible to identify the landlord by examining Griffith's for the surrounding areas - the largest lessor is the likeliest candidate. If the immediate lessor in Griffith's is not the landlord, but a middleman, then it can be useful to try to find this middleman's own holding or residence and see who he is leasing from. Two publications may be of value: O. H. Hussey de BURGH's, "The Landowners of Ireland" provides a guide to the major landowners,, the size of their holdings, and where in the country they were situated. Also "Landowners in Ireland: Return of owners of land of one acre and upwards...." London: 1876 - (note, subsequently republished. by Genealogical Publishing Co.) - is comprehensive but organized more awkwardly, alphabetically within county. Despite all the problems, research in estate records can be very rewarding, per Mr. Grenham - especially for the period before the major 19th century surveys. For example - the rent rolls of the estate of Charles O'HARA in Cos. Sligo and Leitrim, which date from c. 1775, record a large number of leases to smaller tenants, and supply the lives named in the leases, often specifying family relationships. It must be emphasized, however, that information of this quality is rare: the majority of the rentals and tenants' lists surviving only give details of major tenants. A more detailed guide to the dates, areas covered, and class of tenants recorded in the estate papers of the National Library and National Archives are in the process of preparation by the Genealogical Office. (As of the mid 1990s, Cos. Cork, Leitrim, Galway, Mayo, Roscommon and Sligo had been covered). You might want to see what your local LDS (Mormon) Family History Center has regarding the above. SPECIAL NOTE -- The Valuation Office (Dublin) also has maps and record books from the time of the mid 1800s Griffith's Valuation to the present with all transactions on particular parcels of land. This information can be extremely useful, but you do need to have a very good idea of location beforehand, and there is a charge. Check out their website for more details.