At this time he also extended Nantclwyd y Dre by adding a south range to the medieval house, including a parlour, a bedchamber and a two-storey north-west wing, all of which still exist.
He had but one daughter – Mary – and at the death of her father she inherited a thousand-acre estate in and around Llanelidan as well as Nantclwyd y Dre.
Eubule, like his father, was a very sober lawyer, and a record shows that in 1701 he ordered constables to apprehend those who profaned the Sabbath by dancing, playing bowls or tennis.
[5] He married Susan, daughter of Sir Roger Puleston of Emral, Flintshire and when he died in 1713 the main line of the Thelwalls of Nantclwyd ended.
The main estate of Nantclwyd was inherited by his daughter, Martha, who married Andrew Kenrick of Cernioge.
In 1873, Major Walter Clopton Wingfield (1833–1912) introduced friends at the estate to lawn tennis, calling "Sphairistike".
He hired architect Clough Williams-Ellis (1883–1978) to reduce the main house in size, removing wings at the rear, adding a new south elevation facing a new formal garden, gates and gazebos on the site of the demolished parts, with a fibreglass temple, stables with a clock tower, a ceremonial arch, a bridge carrying the drive over the river, and a dovecote.