Isca Dumnoniorum other discoveries at the city's Royal Albert Memorial Museum. Isca Dumnoniorum Isca Dumnoniorum, also known simply as Isca, was a town in the Roman province of Britannia at the site of present-day Exeter in the English county of Devon in the United Kingdom. It served as the tribal capital of the Dumnonians under and after the Romans. The city walls of Exeter (some 70% of which survive) mark the former perimeter of Isca and excavations in the 1970s and 1980s verified that the town was home to a Roman fortress almost certainly for the Second Augustan Legion. The town seems
Isca Augusta River Usk. The suffix "Augusta" appears in the Ravenna Cosmography and was an honorific title taken from the legion stationed there. The place is commonly referred to as "Isca Silurum" to differentiate it from Isca Dumnoniorum and because it lay in the territory of the Silures tribe. However, there is no evidence that this form was used in Roman times. The later name, "Caerleon", is derived from the Welsh for "fortress of the legion". Isca was founded in AD 74 or 75 during the final campaigns by Governor Sextus Julius Frontinus against the fierce native tribes of western Britain, notably