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
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,