Dumnonia until they submitted to the See of Canterbury in the mid-9th century. Parish organisation was a later development of fully Normanised times. Around AD 55, the Romans established a legionary fortress at "Isca Dumnoniorum", modern Exeter, but west of Exeter the area remained largely un-Romanized. Most of Dumnonia is notable for its lack of a villa system, though there were substantial numbers south of Bath and around Ilchester, and for its many settlements that have survived from the Romano-British period. As in other Brythonic areas, Iron Age hillforts, such as Hembury and Cadbury Castle, were refortified in post-Roman times for
Southern England Chalk Formation name of the Western Downs is given. The Downs enclose the rich district of the Weald, where the chalk has eroded to form a much flatter landscape. In Wiltshire is Salisbury Plain, the Wiltshire Downs, and Cranborne Chase, all three famous for their archaeology, and it was on these downs that Augustus Pitt Rivers developed the methods of modern archaeological field work in the 19th century. The Berkshire Downs and White Horse Hills adjoin the northernmost part of this formation. The formation called Cranborne Chase () is a chalk plateau in central southern England, straddling the counties Dorset, Hampshire and