- The Dunamon estate was held under a lease for 500 years from John King, Lord Kingston to Thomas Caulfeild, dated 1 May 1688. The estate proprietor in the late 18th century was Colonel John Caulfeild of Donamon, who was a younger son of the Reverend Charles Caulfeild, and a grandson of William Caulfeild 2nd Viscount Charlemont. In 1828 St. George Caulfeild and Col William Caulfeild were members of the Grand Panel of county Roscommon. In the mid 19th century the Caulfeild estate was in the parishes of Ballynakill, Dunamon and Oran, barony of Ballymoe and Kilbride, barony of Ballintober South, Kilbride and Lissonuffy, barony of Roscommon, county Roscommon. In the 1870s St George Caulfeild owned 4,604 acres in county Galway, 6,632 acres in county Roscommon and smaller acreages in counties Kilkenny, Tipperary (824 acres) and Tyrone. On 21 Mar 1912 over 10,800 acres in county Roscommon belonging to A. St George Caulfeild were vested in the Congested Districts' Board. Much of the Caulfeild estate in county Galway was transferred to county Roscommon when the county border changed in 1898.
- In the mid 19th century Lieutenant Colonel Thomas M. Peers Williams held an estate in the parishes of Dysart and Taghmaconnell, barony of Athlone, county Roscommon. In the 1870s he owned 3,062 acres in county Roscommon. His address was Middlesex, England. Lieutenant Colonel Thomas Peers Williams was a grandson of Thomas Williams of Anglesey and Catherine Lloyd. His seat is recorded as Temple House, Great Marlow, Buckinghamshire. His son Owen Lewis Cope Williams married a daughter of St George Francis Caulfield of Donamon.