Limes Britannicus rapidly to the west and north. Many regions of Britain continued to be governed by the Roman model even after the Romans left, but this practice soon ceased with the continuous encroachment of Anglo-Saxon renegades. With the collapse of the old administrative districts into independent small kingdoms, the jointly maintained provincial army also lost its Roman character. Four years after the Roman invasion, the conquered territory extended roughly as far as a line from Exeter " (Isca Dumnoniorum) " to Lincoln " (Lindum Colonia)", an important intra-Britannic transport hub. Around 55 AD the main camp of the "Legio II Augusta"
Isca Augusta legion was needed to repel a potential invasion from the Continent. The stone from Isca may have been used for building defences on the south coast. There may still have been an occasional military presence as late as the early 4th century, but the fortress was probably later taken over by the people of the surrounding vicus. The basilica of the baths was used as a cattle pen. Recent finds suggest Roman occupation of some kind as late as AD 380. According to the Gildas (followed by Bede), Roman Caerleon was the site of two early Christian martyrdoms in Britain,