Isca Dumnoniorum 28 cities of Britain by the "History of the Britons" as Isca, although Ford read it as a reference to Penselwood and thought it more likely to be Lindinis (modern Ilchester). Isca was also known to the British as Caer Uisc but, after the Roman withdrawal from Britain around 410, there is very little evidence of habitation in Exeter for almost 300 years except for the remains of a building (possibly a church) in the area of the demolished forum and a few nearby graves dated to the 5th, 6th, and 7th centuries. After this, the historical record picks up
England–Wales border Silures, traditionally the area between the rivers Usk, Wye and the Severn estuary. It was centred at different times on "Venta" (Caerwent), from which it derived its name, and "Isca Augusta" (Caerleon). Gwent generally allied with, and at various times was joined with, the smaller Welsh kingdom of Ergyng, centred in present-day southern Herefordshire west of the Wye (and deriving its name from the Roman town of "Ariconium"); and the larger kingdom of Glywysing in modern Glamorgan. The name Glywysing may indicate that it was founded by a British native of "Glevum" (Gloucester). The Battle of Mons Badonicus, circa 500,