Oxford Castle (England)

According to the Abingdon Chronicle, the castle of Oxford it was built by the Norman baron Robert D'Oyly old from 1071 to 1073. D'Oyly went in the British Isles in 1066 on the occasion of the Norman conquest, under the command of William the Conqueror (who had promised numerous lands in Oxfordshire). Oxford then became the scene of numerous clashes, and William D'Oyly advised to erect a castle dominating the village. In due course, of Oyly it became the most important landowner in Oxfordshire; among his possessions there was also the castle of Oxford. The latter appears in the Domesday Book of 1086, but note that the document was not exhaustive, so that numerous English forts were absent.

D'Oyly placed the castle in the western part of the city, taking advantage of the natural protection offered by a tributary of the Thames, now called Castle Mill Stream, even diverting the flow to produce a moat. It is not yet certain whether the manor insist on a pre-existing settlement; although it is clear the nature of an 'urban castle, "difficult to understand the demolition of properties on the site chosen. The Domesday Book does not record any demolition, so the land was probably already inhabited, because of the damage caused by the Norman conquest of the city.
The original building was probably a great motte and bailey, very similar to the structure ever built by D'Oyly in Wallingford, 19 km from Oxford. A castle motte-and-baily consists in a sort of mound (motte) - which usually stands a dungeon or a tower - and a bailey, or an enclosed courtyard, surrounded by a fence. The motte was originally 18 meters high and 12 wide, reinforced (as the bailey) from layers of gravel and clay reinforced facing.
Around the twelfth century, the castle was involved a number of interventions; the latter allowed in 1074, the building of the St George's Tower, a tower of 9 m × 9 m tapering upward to remain stable. It was the largest castle tower, a characteristic attributable to the favorable location of the hotel, facing the ancient gateway to the west of the city access.

Along the walls it was arranged a chapel, probably built in the old church site. The chapel, dedicated to St. George, is the structure of a single nave and is a typical Norman architecture expression.
At the beginning of the thirteenth century, the wooden tower placed on top of the motte was replaced with a stone tower made decagonal, 58 m high and very similar to that of Arundel Castle. The tower, although it constituted a significant footprint for the inner courtyard (restricted only 7 meters), it was still essential in case of siege: in it, in fact, was placed a well.