River Wye given a Latin name "Vaga", an adjective meaning 'wandering'. The Tithe map references a Vagas Field in both Whitchurch and Chepstow. Philologists such as Edward Lye and Joseph Bosworth in the 18th and early 19th centuries suggested an Old English derivation from "wæg", "wave". The source of the Wye is in the Welsh mountains at Plynlimon. It flows through or past several towns and villages including Rhayader, Builth Wells, Hay-on-Wye, Hereford (the only city on the River Wye), Ross-on-Wye, Symonds Yat, Monmouth and Tintern, meeting the Severn estuary just below Chepstow. Its total length is . The lower of the
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,