Thorverton River Exe (near to the current day bridge), a key crossing for the military garrisoned at Exeter (Isca Dumnoniorum). There is no evidence however to suggest that there was a settlement here by the time of the Domesday Book in 1086, although Thorverton Mill was running at this time on the River Exe (and continued to do so until its closure in 1979). (Raddon, a hamlet W of Thorverton is mentioned in the Domesday book. "William holds RADDON (in Thorverton) from the abbott. Wulfmaer held it in TRE, and it paid geld for 1 virgate of land. There is land
Isca Augusta and timber ramparts of the fortress were strengthened by the addition of a stone revetment at the front. This "composite" rampart consisted of a stone wall 5 to 5½ feet thick, backed by a clay bank and fronted by a single ditch By 120 AD, detachments or vexillations of the legion were needed elsewhere in the province and Isca became more of a military base than a garrison. However, it is thought that each cohort still maintained a presence at the fortress. When Septimius Severus seized power in the 190s, he had Isca refurbished and the legion were in residence