[citation needed] His origins are obscure, but after acting as one of the principal supporters of Henry I in his struggle against his brother Robert Curthose for control of the English throne, de Redvers was rewarded with estates that made him one of the richest magnates in the country.
William the Conqueror had bequeathed Normandy to his eldest son Robert, but Henry had bought parts of it from him—including the Cotentin where Néhou, the de Redvers principal possession, was located.
Since de Redvers also owned land in the Vexin which was retained by Robert, he had two lords, and evidently chose to support the one under whom his main property lay.
[8] Richard's manor at Mosterton does not appear in the Redvers family records after about 1090 and it may therefore have been forfeited due to his support of Henry against William Rufus.
In addition to these he still held his estates in Normandy in the Cotentin (at Néhou) and Vexin (at Vernon) and he had also acquired the manors of Crowell in Oxfordshire and Woolley in Berkshire on his marriage.
[12] After the grants from the king, Richard's Devon estates probably consisted of around 180 Domesday manors, including Tiverton and Honiton, as well as the boroughs of Exeter and Plympton.
He held virtually all of the Isle of Wight (the exceptions being two manors held by the bishop of Winchester),[13] and the island remained in his family until 1293 when King Edward I bought it (together with other manors including Vauxhall, South Lambeth, in Surrey), from Isabel de Forz, 8th Countess of Devon (1237–1293), sister and heiress of Baldwin de Redvers, 7th Earl of Devon (1236–1262), shortly before her death.
[14] According to Robert Bearman, Richard de Redvers can confidently be rated among the twelve wealthiest barons of the time, with estates worth well over £750.