- The Smyths were settled in county Waterford from Elizabethan times. In the 17th century Richard Smyth of Ballynatray, county Waterford, married as his second wife Alice, daughter and co heir of Richard Grice of Ballycullane, county Limerick, and had a son Grice Smyth from whom descend the Smyths of Ballynatray. In the mid 19th century Ballynatray passed by marriage to Charlotte Mary wife of Charles William Moore, who succeded his brother as Earl Mount Cashell. They took the additional name of Smyth. In November 1861 their estate of 1,673 acres in the barony of Coshlea and liberties of Kilmallock, county Limerick (the Grice estate) was advertised for sale. In the 1870s the Honourable C.W.M. Smyth of Ballinatray owned over 7000 acres in county Waterford as well as 272 acres in county Limerick. In the 1890s Ballynatray was inherited by the eldest daughter of Earl Mount Cashell, Lady Harriette Gertrude Isabella Smyth, who had married in 1872 Colonel John Henry Graham Holroyd. They assumed the name of Smyth.
Captain J.R. Smyth who owned 799 acres in county Tipperary and 2 acres in county Dublin in the 1870s may have been a member of this family. His agent was James Cahill of Blenaleim, Carrick on Suir.
- In the late 17th century Stephen Moore purchased the Kilworth estate in county Cork. In the 1940s local sources suggested to the Irish Tourist Association surveyor that Moore had purchased it from the Fleetwoods for £600. His grandson, also Stephen Moore, was created Viscount Mountcashell of the city of Cashell in 1766. The Viscount's son became the Earl of Mountcashell in 1781. At the time of Griffith's Valuation the Earl of Mountcashell's estate was located in the parishes of Clondulane, Kilcrumper, Kilworth and Macroney, barony of Condons and Clangibbon, county Cork and in the parish of Shanrahan, barony of Iffa and Offa West, county Tipperary. An estate of 3,971 acres in the barony of Condons and Clangibbon belonging to the Earl was advertised for sale in November 1854. The Freeman's Journal reported that Charles Hunt had purchased some of the Earl of Mountcashel's estate in Clonmel and in county Cork in 1855. The Earl's life interest in 7,160 acres in the barony of Condons and Clangibbon was advertised in March 1864. Later that year the Earl's life interest in 3,873 acres in the barony of Iffa and Offa West, county Tipperary, was advertised for sale. Lands in the baronies of Orrery and Kilmore and Condons and Clangibbons, belonging to Stephen, Earl of Mountcashell, assignee of William Crofts, a bankrupt and others were advertised for sale in May 1856. In the 1870s he owned 5,961 acres in county Cork and 94 acres in county Tipperary. The 3rd Earl's second son ,Charles William Moore, married Charlotte Smyth of Ballynatray, county Waterford in 1848 and in 1858 assumed the additional name of Smyth. He later became the 5th Earl Mountcashell. The remains of the Moorepark demesne and estate were purchased in 1903 by the War Department from Lady Harriette Holroyd Smyth, daughter of the 5th Earl Mountcashell.
In the 1870s Edward G. Moore of Windsor, England, owned 1,082 acres in county Tipperary. The Reverend Edward George Moore, canon of Windsor, was the second son of the 2nd Earl of Mountcashell and died in 1876. He was the father of the 6th Earl.
Armstrong (Cork & Armagh)
- John Tew Armstrong, a solicitor of Dominick Street, Dublin, was a younger brother of William Jones Armstrong of Armagh. John T. Armstrong appears to have purchased some of the Mountcashell estate in the barony of Condons and Clangibbon, county Cork. In November 1865 his estate at Boolabwee and Coolaneague amounting to over 400 acres in the barony of Condons and Clangibbon, was advertised for sale. In the 1870s he owned 527 acres in county Meath and his nephew Henry B. W. Armstrong owned over 4,000 acres in counties Armagh and Longford.