An Anglo-French study has revealed that long before the English Channel there was a giant river which ran south from an area of the North Sea.
Previous research found that 500,000 years ago a range of low hills connected Britain to Europe between the Weald in South-East England and Artois in northern France.
But during a series of ice ages beginning 450,000 years ago huge ice sheets covered much of northern Europe, trapping a portion of the North Sea the size of East Anglia.
The great rivers of Europe poured into this lake at the southern end of the North Sea.
To the north it was bordered by glaciers and to the south by the low-lying land mass connecting Britain to France.