Romney Marsh lies at the frontier between land and sea. It consists entirely of land gained from the sea, and being below the level of high tides, has always been threatened by flooding. Four ports now stranded miles from the sea and another lost to the sea bear witness to great changes in the coastline. The book charts the history of human occupation of a very specialized and difficult environment over the last 2000 years. Advances were made when both environmental and economic conditions were favorable. But when difficulties became insuperable, especially in Roman times and again in the 13th century, the inhabitants retreated. The struggle for survival continues, and the book concludes with the challenges facing the 21st century.