DOE survey of Castle, Castle Park, Colchester. Grade I. Built late C11 on the site of the great Roman Claudian Temple (the foundations still exist under the castle), almost entirely of Roman tiles and septaria. It was probably built in c.1080 for William the Conqueror as an important defensive work. It was much larger and more massive than any other Norman Castle built in England- possibly partly because it had to enclose the great Roman foundations still existing on the site, It had 3 storeys or more and is now probably half its original height, though still a most imposing structure and a most important example of medieval military architecture. Demolition was begun in 1693, the height being reduced. Considerable restoration took place in the mid C18 for Charles Grey. The dome over the great staircase was added by James Deane in 1760. <1>