For centuries, the inhabitants of the Netherlands have had to protect themselves against the sea and the rivers. The low-lying parts of the country, formed by the delta of three major rivers (the Rhine, the Maas and the Scheldt), have suffered disastrous flooding on many occasions. Dwelling mounds, dikes, windmills, sluices and dams have all been used in the ceaseless struggle against the waters. For centuries, things have gone well. And then, in February 1953, a rare combination of a spring tide and a hurricane-force northwesterly gale produces a new catastrophe. The dikes in Zeeland and on the islands of South Holland give way and in the night of 31 January to 1 February more than 1800 people drown, thousands of farm animals are lost and 150,000 hectares of land are inundated. The disaster prompts the launch of the Delta Plan for improved flood defences.