The North Sea has an extensive history of maritime commerce, resource extraction, and warfare between among the people and nations on its coasts. Archaeological evidence shows the migration of people and technology between continental Europe, Britain, and Scandinavia throughout prehistory. The earliest records of Roman explorations of the sea begin in 12 BC. Southern Britain was formally invaded in 43 AD and gradually assimilated into the Roman Empire, leading to sustained trade across the North Sea and the English Channel. The Germanic Angles, Saxons, and Jutes from Frisia and Jutland began the next great migration across the North Sea during the Migration Period, conquering, displacing, and mixing with the native Celtic population in Britain. The Viking Age began in 793 and for the next