Gloucester Castle
There were 2 medieval castles in Gloucester’s history. The first or ‘old’ castle was mentioned in the Domesday Book – it lay to the east of the prison site and was built in the corner of the old Roman town walls. This was most probably of the wooden motte and bailey type.
The old castle was replaced by a new stone castle on the current site c. 1110-1120. The castle was a large structure, with the keep, ... an inner bailey and stables. The keep was surrounded by a series of concentric defences which comprised curtain walls and ditches, with the drawbridge and gatehouse lying outside the current site to the north.
The castle fell into decline during the later medieval period and was taken over as the county gaol during the reign of king Richard III (r. 1483-1485) with the castle keep being the main prison building.
http://cotswoldarchaeology.co.uk/excavating-gloucester-prison/
http://www.follypublications.co.uk/product/the-castles-of-gloucestershire-and-bristol/
18th century engraving of Gloucester from south
http://www.medart.pitt.edu/image/england/gloucester/cathedral/Glouc-SCENE-RGC-F2-b.jpg
