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 Dumnoniorum ha). There is evidence of copper and bronze working. A possible stock-yard has also been identified and Isca was clearly a key market for livestock, crops, and pottery produced in the surrounding countryside. The importance of Isca as a trading centre is demonstrated by the discovery of more than a thousand Roman coins around the city. However, the dates of these coins suggest that the city was at its most prosperous in the first half of the 4th century; virtually no coins dated after 380 have been found, suggesting a rapid decline. Bishop Ussher identified the Cair listed among the