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 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