Romans
At the time of the Roman conquest, the Winchester area was in the territory of the Atrebates tribe, allies of Rome. Roman Winchester was the 5th largest town in Britain and one of the first to receive defences. Archaeology suggests the town reached its peak of population and development in the early 4th century.
The Romans came to Britain in 43AD and departed in 410AD. (The were not the first invaders; about 250 years earlier Britain had been invaded by the Belgic people.) The Romans founded many of today's modern towns and cities in England. In about 75AD, under the reign of Vespasian, the Romans began to build a fortified city, which they called 'Venta Belgarum', what we today call Winchester.
At first Winchester was protected by ditch and an earth rampart, probably with a wooden palisade on top. However at the beginning of the 3rd century Winchester was given stone walls and the city now covered 144 acres, which made it the 5th largest town in Roman Britain.
Very little remains from this period, as the remains from this time are now 12 feet below present day level. But the High Street still runs along the east-west axis as laid out by the Romans and many of the roads leading into the city also follow the original Roman roads. The City Museum has a display of Roman artefacts and mosaics that have been unearthed in various archeological digs in the city.