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
Isca Dumnoniorum Fosse Way, and on the 7th-century Ravenna Cosmography, where it appears as the apparently confused entry of . The fortress was given up around 75 and shortly afterwards its grounds were converted to civilian purposes. The military baths were too large for the local population and were largely demolished, although parts were incorporated into the forum and basilica built on the site. A smaller bathhouse was then built to the southeast. In the late 2nd century, the ditch and rampart defences around the fortress were replaced by a bank and wall enclosing a much larger area, some 92 acres (37