St. Lucia's flood

St. Lucia's flood (Sint-Luciavloed) was a storm tide that affected the Netherlands and Northern Germany on 14 December 1287 (the day after St. Lucia Day), killing approximately 50,000 to 80,000 people in the sixth largest flood in recorded history. Meteorologically this disaster was similar to the North Sea flood of 1953, when an extreme low pressure system coinciding with a high tide caused a huge storm surge. The St. Lucia flood had a major influence on the subsequent history of the Netherlands.

The name Zuiderzee "Southern Sea" (from a Frisian perspective) dates from after this event, as the water had before been a freshwater lake that was only directly connected to the North Sea by the former river Vlie. The St. Lucia's flood removed the last of a series of natural sandy (dunes) and boulder clay barriers after which the new, now salty Zuiderzee came into existence and grew rapidly, this since the peatlands behind the barriers that had disappeared were mostly not protected anymore against erosion from the sea. The coming into existence of the Zuiderzee was the undoing of the powerful medieval trading city of Stavoren at the rightbank of the now disappearing river Vlie and the making of first the IJssel Hanse-cities of Kampen, Zwolle, Deventer, Zutphen and Doesburg and later the anti-Hanseatic city of Amsterdam, that began its rise from nothing to the foremost trading city in the world in the mid 17th century almost immediately after the St. Lucia's flood.

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