Doggerland is the name archaeologists have given to an area of land between Britain, the Netherlands, Germany and Denmark which is now under the North Sea.
At the start of the Mesolithic, around 11,000 years ago, Doggerland was a very large area and would have been lived in by numerous groups of people.
As a result of climate change and sea level rise from the melting of glaciers after the last ice age Doggerland gradually flooded. It got smaller and smaller until by the middle of the Mesolithic Britain finally became an island, about 8000 years ago.
Until that time Doggerland would have provided a connection between Britain and Europe, people would have traded and exchanged things, and might have spoken a common language.
After Britain became an island, people would have needed boats to travel to the rest of Europe. From this time onwards archaeologists find less evidence for contact with the continent during the rest of the Mesolithic.
By about 6,000 years ago the coast of Britain looked much as we would recognise it today.