[Illustration: FIG. 24. PLAN OF QUEENBOROUGH CASTLE, KENT] The main interest of this castle consists in its plan, which proves it to have been perhaps the earliest example of a fort as distinct from a typical castle of the middle ages, in which there was always a certain amount of accommodation for dwelling-house purposes. Queenborough Castle contained, mainly in its six lofty circular towers, more than fifty rooms, but these were of small size. The building of the castle was commenced in 1361 and finished about the year 1367. The plan was curiously symmetrical, and not unlike that of Camber Castle, built in the time of Henry VIII, but the elevations of the two fortresses display great differences. The lofty towers of Queenborough, serviceable enough in the fourteenth century when artillery attacks offered no serious menace, are wanting in Camber Castle, built in the sixteenth century, and their place is taken by low squat towers which offered little surface for cannon-shot. [Illustration: FIG. 25. QUEENBOROUGH CASTLE, 1784 From a drawing by Hollar] _Canterbury._--There were really two castles at Canterbury in quite early times. The first, largely perhaps of earthwork, was the work of Duke William of Normandy, and was constructed on and near what is now the most southern point of the city wall. The purpose of the first castle was to dominate and overawe the inhabitants of the city, and also to furnish a convenient post for observing the surrounding country. The castle was provided with a lofty moated mound for this particular purpose. The hill called the Dane John has sometimes been confounded with the original mound of the castle, but as a matter of fact the two were not related in any way, the castle mound having been destroyed many years ago, whilst that known as the Dane John was erected in the eighteenth century. The masonry castle, the ruined keep of which stands to the north-west of the earlier castle, was built by Henry II between 1166 and 1174. The keep measures in plan 88 feet by 80 feet, and, owing to the upper storey having been pulled down in 1817, measures now only 45 feet in height. The castle was originally enclosed by a rampart and wall with several towers, and had its own gate to the city, and a barbican on its eastern side. [Illustration: FIG. 26. CANTERBURY CASTLE IN THE EIGHTEENTH CENTURY]