Burke indicates that the Trenches originated in France but settled in the North of England. Frederick Trench came to Ireland in the 1630s and purchased the castle and lands of Garbally. Successive generations represented county Galway in parliament. Willam Power Keating Trench was created Earl of Clancarty in 1803. The Clancarty estate was one of the largest in county Galway in the 19th century. In 1824 Lord Clancarty is described as a resident proprietor in the county. At the time of Griffith's Valuation, the estate owned property in the baronies of Clonmacnowen, Dunkellin, Kilconnell and Loughrea. In the 1870s the Earl of Clancarty owned almost 24,000 acres in county Galway as well as over 1600 acres in county Roscommon.
Property in Ballinasloe town. leased from the Clancarty estate by James Edward Ward, was offered for sale in the Encumbered Estates court in January 1858.