Isca Dumnoniorum again around 680 with a document that reporting that St Boniface was educated at the abbey in Exeter. Much of the Roman wall survives as the lower courses or inner core of the medieval city walls, 70% of which still exist, largely built on the orders of Alfred the Great to protect the far west of his kingdom following the Viking occupation of 876. The legionary bath complex was excavated in the 1970s, but because of its proximity to the cathedral it was not practicable to retain the excavation for public view. Artifacts from the excavation, however, are displayed with
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