 He was Constable of Portchester Castle from 1421 until his death, Sheriff of Surrey and Sussex for 1422 and 1434, Treasurer of the Household for King Henry VI between 1439 and 1446, Keeper of the King's Wardrobe, and Chief Steward of the Duchy of Lancaster from 1441 to 1447.He financed the initial construction of Herstmonceux Castle with spoils from the Hundred Years' War.Roger Fiennes was ultimately responsible for the construction of Herstmonceux Castle in the County of Sussex.