In the medieval period the Netherlands, whose name literally means ‘lower countries’, consisted of large areas of boggy land around the winding estuaries of three of the largest rivers in Europe. Although prone to flooding, the fertile areas close to the sea had attracted many settlers by the 10th century and, by the turn of the millennium, the population began to increase rapidly.
The construction of dikes to hold back the sea consequently became an important part of life in the area. Draining the peat bogs that were left behind provided arable land to feed the growing population, but it also made the ground sink by up to a metre every century.
On 14 December 1287, the day after St. Lucia’s Day, an extreme low pressure system coincided with high tide in the North Sea to cause a huge storm surge that rose far above the usual sea level. The waves battered the dikes built to defend the north and northwestern part of the Netherlands, and poured onto the land below. Numerous villages were destroyed, and records indicate that at least 50,000 people lost their lives.
Meanwhile the floodwaters transformed a shallow freshwater lake into the salty Zuiderzee and created direct sea access to what was then the village of Amsterdam. The flood was therefore directly responsible for the development of one of the world’s leading port cities.
The English coastline was also severely affected by the storm. Although the number of casualties was considerably lower, other effects were just as significant. Combined with another huge flood that had struck southern England in February numerous ports declined after being silted up, while new ones soon appeared.