- The Mathew family of Thomastown, county Tipperary had close connections in the 17th century with the Butler family, Earls of Ormonde. George Mathews of Reaghill was granted a large estate in county Tipperary by patent dated 1666 including part of Thomastown. In 1760 Thomas Mathew of Annefield succeeded to the Mathew estates of Thomastown and Thurles. Thomas was succeeded by his son Francis in 1777 who was created Earl of Llandaff in 1797. In 1764 Francis married Ellis Smyth of Tinny Park, county Wicklow and had three sons and one daughter who all died childless. Their daughter, Elizabeth, left the estates to her cousin, Viscount Chabot, her mother's nephew, who succeeded in 1842. In 1840 the Ordnance Survey Name Books record the ownership by "Lady E. Mathew" of townlands in the parish of Kilfeacle, barony of Clanwilliam. The birthplace and early home of Father Mathew 'The Apostle of Temperance' whose father was a cousin of the 1st Earl of Llandaff and for whom he worked as agent. Mark Bence Jones in an article about Thomastown Castle in ''County Life'' (2 Oct 1969) records the purchase in 1938 of the ruin and 20 acres by Archbishop Mathew, a family connection, to save it from destruction.
- In 1777 Elizabeth, sister of Sir Skeffington Smyth of Tinny Park, county Wicklow, married the Comte de Jarnac, Viscount Chabot of the Rohan family of France. Their son Major General Louis William de Rohan-Chabot, Viscount Chabot married Isabell Charlotte, daughter of the 2nd Duke of Leinster, in 1809. Lady Elizabeth Mathew died in 1842 and left the Mathew, Earl of Llandaff, estates in county Tipperary to her cousin the Viscount Chabot. In the mid 19th century the Chabot estate was located mainly in the parish of Templemore, barony of Eliogarty and in the parishes of Kilfeakle and Relickmurry and Athassel, barony of Clanwilliam, county Tipperary. In June 1859 the Manor of Thurles, 1,713 acres in the barony of Eliogarty and part of the Thomastown estate containing 2,378 acres in the barony of Clanwilliam, belonging to Viscount Chabot, were advertised for sale. The sale did not include Thomastown Castle. The Viscount died in 1875.
- Robert George Massy of Avondale, county Dublin, was a grandson of the 1st Baron Massy by his second wife Rebecca Dunlap. He married a Miss Sutton and had a son William. At the time of Griffith's Valuation Robert G. Massy held lands in the parishes of Kilfeakle and Relickmurry & Athassel, barony of Clanwilliam from Viscount Chabot.