Changes of sea-level, retreat of shorelines have occurred throughout geological times. They have taken a special significance since Man has appeared. Man has been simultaneously awed by the sea and attracted by its shores. He has consistently attempted to protect his settlements against the onslaughts of the sea. Coastal defenses can be traced back to remote times. It is probable that dams or walls were erected before the Frisians did, but their “defenses” were described by Pliny, and, jusqu'à preuve du contraire, are considered as the first “dike builders”.
Earthen artificial hillocks are the forerunners of stone constructions built to hold back the advances of the sea, particularly when sizeable areas of land were gobbled up by the waters along coasts, but also in estuaries, witness i.e. the Dutch Verdronken Land van Saeftingen. The groins, seawalls, breakwaters and the like proved to be illusory shields, to solve little, but to create new problems.
Engineers and scientists tried different approaches, inspired by Nature's own ways, nourishment for instance. Other methods are being honed. They must as well consider the economic and social impacts of coastal erosion. The paper follows the historical evolution of man's attempts to retain his “land”.