Sub-sub-fonds AG - Glamorgan estate,

The Glamorgan estate was founded on the Ruperra estate. The name 'Ruperra' is an anglicized form of Rhiw'rperrai (now often Rhiwperra in Welsh). Sir Ralph Maelog, lord of Cibwr and Rhiw'rperrai, was succeeded by Maud, his daughter and heir, who married Einion ab Sir Owain Ddu (prob. fl. early 13 cent.). Their descendant David ab Ieuan of Blaenbradach married Maud (or Ann) daughter of Morgan ap Llywelyn (d. pre-1384) of Tredegar, and had two sons and one daughter. Llywelyn the eldest son gave rise to the Thomas family of Llanbradach, while Gwilym the younger son gave rise to the Lewis family of Rhiw'rperrai. The Lewis family failed in the male line with Catherine (or Margaret in some accounts) Lewis, daughter and heir of Rowland Lewis of Rhiw'rperrai.

She married aged 21, sometime between 1586 and 1589, with Thomas Morgan (b. c.1564), sixth son of Edmund Morgan (d. pre-1595) of Penllwyn-sarth in the parish of Mynyddislwyn, the son of Thomas Morgan (fl. 1538) of Machen. Thomas Morgan built Ruperra House or Castle and the Ty Coch or Red House in Cardiff (later the Cardiff Arms Inn) for a reputed £19,999 19s. 9d.; he was sheriff of Glamorgan 1617, steward to William, earl of Pembroke, and knighted at Wilton, 1623; he received Charles I at Ruperra 25-29 July 1645 in the final months of the Civil War, and was on the list of delinquents whose estates were to be sold in 1652.

John Morgan ('the merchant', dsp. 1715) bought Ruperra castle and estate in 1706. He made a number of other purchases in Glamorgan, including three parcels in the parish of Rudry bought in 1712 for £102, £226 and £104 10s. respectively (NLW: Tredegar Misc. Vols 198). John Morgan died unmarried in 1715, and his estates were inherited by his nephew and namesake John Morgan (1672-1719) of Tredegar.

The Ruperra appears to have retained its administrative independence from the Tredegar estate at this stage. By the end of the eighteenth century, the same agents were collecting Ruperra and Tredegar rents within some circuits, although the proceeds appear to have been accounted separately by estate.

In 1806 the several rent collections of the Tredegar, Ruperra, Dderw and Palleg estates, were reorganized to form unified county estates. The Ruperra rents in Monmouthshire were separated from the Ruperra estate and incorporated in the new Monmouthshire estate. The remaining Ruperra estate, often called 'the Ruperra estate in Glamorgan' continued for several more years. The term Glamorgan estate first appears in 1847, relating to the Ruperra estate in Glamorgan. The development of Cardiff and other towns during the nineteenth century resulted in the separation of the Cardiff ground rents and a Glamorgan town estate from the main Glamorgan estate.