Winchester more urban settlement type developed, known as an oppidum, although the archaeology of this phase remains obscure. It was overrun by the confederation of Gaulish tribes known as the Belgae sometime during the first century BCE. It seems to have been known as Wentā or Venta, derived from the Brittonic for "town" or "meeting place", or the word for "white" (Welsh "gwyn"), due to Winchester's situation upon chalk. After the Roman conquest of Britain, the settlement served as the capital () of the Belgae and was distinguished as Venta Belgarum, "Venta of the Belgae". Although in the early years of
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,