Hampshire tribes of northeastern Gaul - whether these two events are linked to the decline of hillforts is unknown. By the Roman conquest, the "oppidum" at Venta Belgarum, modern-day Winchester, was the "de facto" regional administrative centre; Winchester was, however, of secondary importance to the Roman-style town of Calleva Atrebatum, modern Silchester, built further north by a dominant Belgic polity known as the Atrebates in the 50s BCE. Julius Caesar invaded southeastern England briefly in 55 and again in 54 BCE, but he never reached Hampshire. Notable sites from this period include Hengistbury Head (now in Dorset), which was a major
Venta Icenorum south of present-day Norwich, and a mile or two from the Bronze Age henge at Arminghall. It lies on the River Tas. The embankments of Venta Icenorum can still be seen at Caistor today. The ruins (British National Grid ref TG230034) are in the care of the Norfolk Archaeological Trust and managed by South Norfolk District Council. Venta Icenorum Venta Icenorum, located at modern-day Caistor St Edmund in the English county of Norfolk, was the civitas or capital of the Iceni tribe, who inhabited the flatlands and marshes of that county and are famous for having revolted against Roman rule