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 their initial invasions, the Romans established a 'playing-card' shaped fort () at the site around 55. It was the base of the strong Second Augustan Legion () for the next 20 years before they moved to Isca Augusta (modern Caerleon in Wales). Both Iscas were also home to their families as settlements are thought to have grown up outside the fortress gates, especially to the north-east. Buildings within the fortress, such as barracks, granaries, and workship (), were timber structures, the post-trenches of which were excavated in the 1970s in advance of the Guildhall shopping centre development. The only known