After the Norman Conquest
At the time of the Norman conquest Oxford had become a fully developed town and to keep Oxford in submission the Norman governor Robert D'Oilly destroyed a number of dwellings to build an impressive castle (1071), which also entailed an extension of the town walls. Remains of the castle can still be seen in St George's tower and in parts of the churches of St Michael, St Peter and St Cross.
Like elsewhere, the upheaval that came in the wake of the Norman conquest also deeply affected Oxford. It is quite reasonable to presume that the town resisted the advance of the Normans and this might account, at least in part, for the difficult times it suffered in later years. The Doomsday Book mentions the destruction of much of the town, which might go some way in explaining Robert D'Oilly's construction of fortifications.
The castle was the scene of an event often remembered. During the upheaval of the reign of Stephen (1135-1154 ) Queen Matilda was besieged there but managed to escape. Dressed in white she walked over the frozen waters of the Thames undetected as her white figure was indistinguishable from the white background of snow and ice.
Oxford had often had close links with royalty. It was the scene of royal councils for example in 1018 when the rule of Canute was officially recognised and in 1065 when Edward the Confessor had to come to terms with rebels, followers of Morcar. After the Norman conquest Henry I built Beaumont Palace near the west side of Beaumont Street and it was in this royal palace that Richard I was born.