Robert D'Oyly (also spelt Robert D'Oyley de Liseaux, Robert Doyley, Robert de Oiley, Robèrt d'Oilly, Robert D'Oyley and Roberti De Oilgi) was a Norman nobleman who accompanied William the Conqueror on the Norman conquest, his invasion of England. He died in 1091. Background Robert was the son of Walter D'Oyly and elder brother to Nigel D'Oyly. D'Oyly is a Norman French name, from the place name Ouilly near Lisieux in pays d'Auge, present Calvados département in Normandy. He married Ealdgyth, the daughter of Wigod, the Saxon lord of Wallingford. After Wigod's death, William appointed Robert the lord of Wallingford, and ordered him to fortify Wallingford Castle between 1067 and 1071. It is believed he may have become the third High Sheriff of Berkshire around this time. He was made Baron Hocknorton. D'Oyly was a sworn brother-in-arms of Roger d'Ivry. The Domesday Book records that by 1086 D'Oyly and d'Ivry held a number of manors either partitioned between the two of them or administered in common. His brother Nigel's son was Robert Doyley, the founder of Osney Priory, Oxford. Nigel was also an ancestor of Henry D'Oyly, one of the major feudal barons of the Magna Carta. "He was so powerful a man in his time, that no one durst oppose him", says one account. At Abingdon he was remembered as "a despoiler of churches and the poor until his miraculous conversion [to Christianity]". The latter was during the economic decline that Oxford experienced between 1066 and 1086; however, it is noted that Robert's own properties suffered as much waste in this period. Legacy Robert was appointed High Sheriff of Oxfordshire and ordered the construction of many parts of Oxford, some of which still survive today. Oxford Castle was built under Robert's orders in 1071, and the collegiate church of St George's within the castle was founded by Robert in 1074. The church of St Peter-in-the-East was first mentioned in 1086 as a possession of Robert's although it is possible that he merely acquired it, along with St Mary Magdalen's Church, north of the former gate of Oxford's medieval wall. The monks of Abingdon credited him with the construction of a series of stone bridges at Grandpont ("The Great Bridge"), which form a causeway over the River Thames. This now forms the major route between the city centre and the south, and the crossing point is near St Aldate's over Folly