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
Venta Silurum Roman temple, perhaps dedicated to Mars and the Celtic god Ocelus, have been identified on the site. A bowl with a chi-rho symbol shows that the worship of early Christian worship had begun in the late 3rd century. Following the withdrawal of the Roman legions from Britain, the town remained occupied until at least the mid-5th century. Early Christian worship was still established. The town might have had a bishop. A monastery was founded by Saint Tatheus in the 6th century. The site of the present church occupies part of an early Christian cemetery. The name "Venta" gave its name