ne of the most important types of building constructed in the time of William the Conqueror and William Rufus were the Norman keeps. The keep had two primary requirements, the first was to provide comfortable accommodation for the noble and his family, and the second was to protect the noble from being attacked. Although many were rebuilt in the following century there are many good examples still remaining. The White Tower in London, Dover and Rochester in the south east, Newcastle, Appleby, Carlisle, Brough, Richmond in the north are all examples of this type of castle. Other examples include Portchester, Guilford, Goodrich, Norwich, Castle Rising, Hedingham and Colchester. A keep was also known as a donjon, a French word. This word was probably altered over the years and its meaning changed so now the word dungeon means a small room used as a prison.