John E. Trench was a significant landowner in the parish of Ballymacward, barony of Kilconnell and the barony of Kilgerrill, barony of Clonmacnowen, county Galway, in 1855. He also held lands in the parish of Clonfert, barony of Longford, which he had purchased on the abolition of the bishopric there in 1834 and in the parish of Clonkeen, barony of Tiaquin and parish of Ahascragh, barony of Killian. Part of the estate of the bishopric of Clonfert was offered for sale in the Landed Estates court in June 1874. This branch of the Trench family were descended from the Trenches of Garbally as well as the Eyres of Eyrecourt and the O'Haras of Annaghmore, county Sligo. In the 1870s they were recorded as owning over 1000 acres in county Galway.
- Landed Estates Court Rentals (O'Brien), Bishopric of Clonfert, 20 June, 1874, Vol 115, MRGS 39/053, (microfilm copy in NUIG).; National Archives of Ireland
- Clonfert Palace. Photographs & Press Cuttings. 003/087.; Irish Architectural Archive
Contemporary printed sources
- PARLIAMENTARY PAPERS. ''Return of owners of land of one acre and upwards, in the several counties .... in Ireland''. HC 1876, LXXX: 300.
- HUSSEY DE BURGH, U. H. ''The Landowners of Ireland. An alphabetical list of the owners of estates of 500 acres or £500 valuation and upwards in Ireland''. Dublin: Hodges, Foster and Figgis, 1878. [available online at www.askaboutireland.ie] : 450.
- ''GRIFFITH'S VALUATION OF IRELAND'[Primary Valuation of Tenements]', 1850-1858. : Ballinasloe Union,122.
- PARLIAMENTARY PAPERS. ''Return of Untenanted Lands in Rural Districts, Distinguishing Demesnes on Which There is a Mansion...'', HC 1906, c, 177: 307.
- PARLIAMENTARY PAPERS. ''Return of names of proprietors and area and valuation of properties in counties in Ireland, held in fee or perpetuity or long leases at chief rents,'' 1876. (412) LXXX. 395: 150.
Modern printed sources
- BURKE, Sir Bernard. ''A genealogical and heraldic history of the Landed Gentry of Ireland''. London: Harrison & Sons, 1912: 704.
- GLIN, Knight of, GRIFFIN, D. J. & ROBINSON, N.K (eds).'' Vanishing Country Houses of Ireland''. Dublin: Irish Architectural Archive/Irish Georgian Society, 1989. : 69
- BENCE-JONES, Mark. ''A Guide to Irish Country Houses''. Revised ed. London: Constable, 1988. : 87
- BLAKE, Tarquin. ''Abandoned mansions of Ireland II: more portraits of forgotten stately homes'' Cork: Collins Press, 2012. : 96-103
- MULLIGAN, Kevin. ''Vain transitory splendours: the Irish country house and the art of John Nankivell.'' Dublin: Irish Georgian Society, 2018. : Clonfert Pa;ace, pp.56-57.
- O'BYRNE, ROBERT. ''The Irish aesthete: ruins of Ireland.'' London: Cico Books, 2019. : pp.118-119 (Clonfert Palace)