Powderham is a former manor on the coast of south Devon, England, situated within the historic hundred of Exminster, about 6 miles (9.7 km) south of the city of Exeter and adjacent to the north-east of the village of Kenton. It consists in part of flat, formerly marshy ground on the west bank of the River Exe estuary where it is joined by its tributary the River Kenn, the site of Powderham Castle, originally the fortified manor house of Powderham. On the opposite side of the Exe is the small village of Lympstone and almost opposite is Nutwell Court in the parish of Woodbury, formerly the castle or fortified manor house of the powerful mediaeval Dynham family.
In the Domesday Book of 1086, the tenant-in-chief of POLDREHA~ (Poldreham) is recorded as William II, Count of Eu (d.1096), listed under the heading: Terra Willelmi de Ow ("Lands of William of Eu"). Although William II, Count of Eu, held many estates elsewhere in England from the king (in Dorset, Wiltshire, Hampshire, etc.), in Devon he was one of the lesser Devon Domesday Book tenants-in-chief with only two Devonshire holdings, Powderham and nearby Whitestone, both sub-infeudated to his tenant Ranulf. William II, Count of Eu, rebelled against King William II (1087-1100) and was executed.
The tenant family holding the manors of Powderham and Whitestone under the overlords, as did Ranulf in 1086, later adopted the surname de Powderham from their seat (as was usual) and continued to hold under the de Bohun overlords until they lost the lands by escheat (see below).