The fortresses of the rapes are also six:—Chichester, probably of Roman origin, long since destroyed; Arundel, Bramber, Lewes, and Hastings, all of præ-Norman date; Pevensey, of Roman origin. Ella, who landed A.D. 477, took possession of Chichester. All were the seats of English lords, and all were accepted by the Normans as well-chosen positions, and by them were occupied and strengthened. Knepp or Knapp Castle, subordinate to Bramber, in the same rape, like it, is of English origin. Of the six castles, three, Arundel, Bramber, and Lewes, are posted at the upper openings of narrow gaps in the chalk downs. Chichester is placed to the east of and outside the chalk range. Pevensey stands within the weald, among the low marshes by which that tract opens upon the sea; and Hastings, also within the weald, stands upon the sea-cliff, on the rocks and sands to which it has given geologically its name. All the six, as well as Knapp, possessed, on a larger or smaller scale, the conical mound so characteristic of English strongholds, and each, after the Conquest, became the chief seat of a barony, and was held by a powerful noble. Robert de Eu had Hastings; William de Warren, Lewes; the Earl of Moreton, Pevensey; Chichester fell to Roger de Montgomery, who there founded a castle upon the site of the earlier works, of which part of the mound remains. The castle stood within the city enclosure, in the north-east quarter. It became, with Arundel, the property of the D’Albinis, and was destroyed by order of King John, after which the third Earl of Arundel founded on its site the Grey Friars, of which the house was probably built with the materials of the castle. It is said that upon the mound stood a circular or polygonal keep, as at Arundel, and that the traces of its foundations were long visible on its summit. The mound has survived all its Norman additions, and is the only relic of the ancient fortress that is extant. The city, within which the castle stood, is also an early strong place. The cruciform streets are, doubtless, Roman, as are the coins and inscribed stones occasionally dug up; but the outline of the city is not rectangular, and is enclosed within a bank and ditch of irregular outline, once of formidable strength, and still in parts tolerably perfect. It is not improbable that these earthworks are post-Roman, the work of the Romanised Britons, and therefore earlier than the date of the castle mounds. The later wall was built against the bank, which thus still, where it remains, forms a broad ramp or terrace. Arundel Castle, next eastwards to Chichester, and its superior in military importance, stands on the right bank of and high above the Arun. The pass is of a more open character than those to the east of it. This castle has already been described. Knepp Castle is in Shipley parish. It had a shell keep upon the mound, of which traces remain, but which is said to have been destroyed as early as 1216.