Zuiderzee

Zuiderzee, meaning Southern Sea, was a shallow bay of the North Sea along the northwest coast of the Netherlands. It stretched along parts of what are now the provinces of North Holland and Friesland, extending from the Wadden Sea in the north to the IJssel river's vicinity in the east. For centuries it functioned as a saltwater inlet with fishing and shipping towns lining its shores.

The Zuiderzee formed through a combination of silting, coastal processes, and dike-building that transformed parts of the coast into a protected inland sea. Beginning in the Middle Ages, storms and flooding repeatedly reshaped the coastline, and the area became more enclosed over time. The region’s openness also made it prone to catastrophic floods, notably the St. Elizabeth’s flood of 1421, which caused widespread damage and spurred further coastal changes and reclamation efforts.

Economically, the Zuiderzee supported a thriving fishing industry, especially for herring, and fostered maritime trade and shipbuilding. Towns such as Hoorn, Enkhuizen, and Stavoren grew as commercial centers, while others along the shore benefited from the sea’s resources and routes to the Baltic and beyond.

Transformation and legacy followed in the 20th century. Between 1927 and 1932, the Afsluitdijk was completed, sealing off the Zuiderzee and turning it into the freshwater IJsselmeer. The Zuiderzee Works then reclaimed large tracts of land, creating polders such as the Noordoostpolder and the Flevopolder; Flevoland province was established in 1986. Today the former Zuiderzee is remembered as a landmark example of Dutch water management and land reclamation.