Dafydd ap Mathew (David Mathew) son of Mathew ab Leaun of LLandaff Court, Glamorgan. His descendant (George Mathew) married Elisabeth Poyntz, from an old Gloucestershire family.
Elisabeth Poyntz was originally married to the Duke of Ormond (Viscount of Thurles, Tipperary). When the Duke died, Elisabeth married George Mathew of Llandaff and he moved to her estates in Tipperary.
Back then lands were not bought but given by the Crown, and George Mathew was given Thomastown, Tipperary, upon which he built Thomastown Castle.
George and Elisabeth moved into Thomastown Castle where they raised a family.
Their descendant, Francis Mathew (1st earl of Llandaff) married Ellisha Smyth of Tinney Park, Wicklow and they had five children, Francis (2nd Earl of Llandaff) George, Montaqu and Ellisha 2.
Ellisha 1 (Lady Ellisha) died giving birth to Ellisha 2, leaving Francis (1st Earl) widowed with five children.
Francis then married Catherine Skiffington, daughter of the Earl of Massereen but she died without issue in (children) 1796. His third wife (name unknown) was a sister to the Countess of Barrymore.
His son Francis (2nd Earl of Llandaff) married Gertrude Cecilia, daughter of John la Touch of Kildare and they had no children. His brothers, George and Montaqu, never married. The three brothers, Francis, George and Montaqu were known about London as the three Mr Wiggins after a farce of that name then playing at the Haymarket. The three brothers also invented the beaver hat. All three died without issue leaving the Thomastown estate to their sister Ellisha, and the Mathew line and title became extinct.
Ellisha Mathew married James Wade from an equestrian family and they set up a stud farm at Thomastown which still exists today. Their descendants include Tommy Wade, international showjumper in the 1960s winning several cups including the 1963 King George Cup. Another descendant is Ellisha Spencer (mentioned by Rymer) from the Wade family but married into the Spencer family.
The first Spencers (brothers, John and Geoffrey) arrived in Ireland as soldiers in the Cromwellian army. Oliver Cromwell divided the Barony of Killure between John and Geoffrey and their descendants still own the lands today.