The Invasion of Britain

The Romans referred to the imperial province as Britannia, which eventually comprised all of the island of Great Britain south of the fluid frontier with Caledonia (Scotland). Before the Roman invasion, begun in AD 43, Iron Age Britain already had established cultural and economic links with Continental Europe, but the Roman invaders introduced new developments in agriculture, urbanisation, industry and architecture. Besides the native British record of the initial Roman invasion, Roman historians generally mention Britannia only in passing, thus, most knowledge of Roman Britain has derived from archaeological investigations, and the epigraphic evidence lauding the Britannic achievements of an Emperor of Rome, such as Hadrian (r. AD 117 38) and Antoninus Pius (r. AD 138 61), whose walls demarcated the northern borders of Roman Britain.

The first extensive Roman campaigns in Britain were by the armies of Julius Caesar in 55 and in 54 BC, but the first significant campaign of conquest did not begin until AD 43, in the reign of the Emperor Claudius.

Following the conquest of the native Britons, a distinctive Romano-British culture emerged under provincial government, which, despite steadily extended territorial control northwards, was never able to exert definite control over Caledonia. The Romans demarcated the northern border of Britannia with Hadrian's Wall, completed around the year 128. Fourteen years later, in AD 142, the Romans extended the Britannic frontier northwards, to the Forth-Clyde line, where they constructed the Antonine Wall, but, after approximately twenty years, they then retreated to the border of Hadrian's Wall.

Around the year 197, Rome divided Britannia into two provinces, Britannia Superior and Britannia Inferior; sometime after AD 305, Britannia was further divided, and made into an imperial diocese.

For much of the later period of the Roman occupation, Britannia was subject to barbarian invasions and often came under the control of imperial usurpers and pretenders to the Roman Emperorship.

Most Romans departed from Britain around the year 410, which began the sub-Roman period (AD 5 6 c.), but the legacy of the Roman Empire was felt for centuries in Britain.