Richard I de Grenville

Sir Richard de Grenville (died after 1142) (alias de Grainvilla, de Greinvill, etc.) was one of the Twelve Knights of Glamorgan who served under Robert FitzHamon (died 1107), in the conquest of Glamorgan in Wales. He obtained from FitzHamon the lordship of Neath in which he built Neath Castle and in 1129 founded Neath Abbey. He is by tradition the founder and ancestor of the prominent Westcountry Grenville family of Stowe in the parish of Kilkhampton in Cornwall and of Bideford in Devon, the later head of which family was John Granville, 1st Earl of Bath (1628–1701). The surname of his supposed descendants the Westcountry Grenville family was spelled by tradition "Grenville" until 1661 when it was altered to "Granville".

As his reward for his services during the conquest of Glamorgan his brother Robert FitzHamon allotted him the lordship of Neath, where Richard built Neath Castle. He is styled in one Glamorgan charter as "Constable of the Earl of Gloucester", thus of Robert Fitzroy, 1st Earl of Gloucester (died 1147), his brother's son-in-law and heir.

In 1129 Richard de Grenville founded Neath Abbey within his lordship as a daughter-house of the Benedictine Savigny Abbey near the village of Savigny-le-Vieux in western Normandy. Following the assumption of the Savigniac order into the Cistercian order in 1147 Neath Abbey also became a Cistercian house. To it he donated many of his lands, both in Wales and in Devon which he held from the Honour of Gloucester, including Littleham, near Bideford in North Devon. A later confirmation charter granted in 1207 by King John (1199–1216) to Neath Abbey confirmed to the monks the former grants of Richard de Grenville:

...
Wikipedia