On the North Sea and Channel shores the Southeastern coast of England holds perhaps the record for the number of towns gobbled up during recent—historic—times. The relative level of the sea to the land has varied over the centuries: in the late Roman period, and again from about 1250 onwards. Protective dykes were constructed but were repeatedly destroyed by the sea. There were periods of accretion that resulted for instance in the creation of the salt marshes of Essex and the Wash. Once flourishing settlements on the eastern coast of England have been completely destroyed, some before, some during the Middle Ages. Some prospering settlements disappeared under the sea in the 14th century, when major flooding occurred several times, with the worst floods in the 15th century. The coast of Flanders—Belgian area and Netherlandish Zeeland—has been the theatre of both silting and erosion. The paper provides a review of physical changes, loss of land, and their economic consequences.