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
New England town were not part of this process in southeastern New Hampshire, such as Exeter. Once there were enough residents in a town to formally organize a town government, no further action was necessary to incorporate. This practice can lead to inconsistencies in the dates of incorporation for towns in this region. Dates given in reference sources sometimes reflect the date when the town was chartered, which may have been long before it was settled, and not the date when its town government became active. In other parts of New England, some "future towns" were laid out along these lines, but such