<P> Doggerland is the name of a land mass now beneath the southern North Sea that connected Great Britain to continental Europe . It was flooded by rising sea levels around 6,500--6,200 BC . Geological surveys have suggested that it stretched from Britain's east coast to the Netherlands and the western coasts of Germany and the peninsula of Jutland . It was probably a rich habitat with human habitation in the Mesolithic period, although rising sea levels gradually reduced it to low - lying islands before its final submergence, possibly following a tsunami caused by the Storegga Slide . </P> <P> The archaeological potential of the area had first been identified in the early 20th century, but interest intensified in 1931 when a fishing trawler operating east of the Wash dragged up a barbed antler point that was subsequently dated to a time when the area was tundra . Vessels have dragged up remains of mammoth, lion and other animals, as well as a few prehistoric tools and weapons . </P>

When did britain become permanently separated from the continent by the channel