Isca Dumnoniorum settlement there (modern Caerleon) to be distinguished as "Isca Augusta", while the Devonian Isca was called "Isca Dumnoniorum": Usk of the Dumnonians. Exeter began as settlements on a dry ridge ending in a spur overlooking a navigable river teeming with fish, with fertile land nearby. Although there have been no major prehistoric finds, these advantages suggest the site was occupied early. Coins had been discovered from the Hellenistic kingdoms, suggesting the existence of a settlement trading with the Mediterranean as early as . This is disputed however by Prof T P Wiseman who alleges the hoard was not genuine. Following
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