The story of this place
Floris V and the struggle for West Friesland
In the late thirteenth century, the counts of Holland tried to extend their authority over the still independent West Frisians. This was not a simple border conflict. It concerned land, trade routes and control over an area where local communities had long remained beyond the direct reach of Holland’s power.
For Floris V, the conflict also had a personal dimension. His father, Count William II, had died in 1256 during a campaign against the West Frisians. According to tradition, he fell through the ice with his horse and was then killed. Floris grew up with the loss of his father and with the political need to restore his authority.
From the 1270s onwards, Floris again exerted pressure on West Friesland. A severe flood in 1287 isolated several areas and made joint resistance more difficult. In the following years, more and more communities were forced to recognise his authority.
A castle that existed for barely fifteen years
Near Wijdenes, Floris probably had a brick stronghold built around 1282. Its waterside position made it possible to control shipping and coastal traffic. The castle served as a base for soldiers and officials and made Holland’s presence visible in a region where that authority was not self-evident.
The stronghold probably existed for less than fifteen years. After the death of Floris V in 1296, the political situation changed rapidly. The West Frisians seized their opportunity and forced the surrender of several fortifications. The castle near Wijdenes was also abandoned.
The building was then deliberately dismantled. How much building material was removed or reused elsewhere is unknown. What is certain is that the castle did not remain standing as a ruin. The bricks disappeared and the site lost its military function.
How the coast swallowed the castle site
The castle site lay close to the coastline of the time. In the following centuries, that coastline changed continually. Storms and erosion removed land, while dykes had to be built further inland.
As a result, not only the castle but eventually also the ground on which it had stood disappeared. What had once been a strategic point on land came to lie on the bottom of the later Markermeer.
This double disappearance makes Wijdenes exceptional. First the stronghold was dismantled by people. Then the water also removed its former site from view.
The search beneath the Markermeer
Historians and archaeologists searched for a long time for the precise location of the castle. Old texts pointed to Wijdenes but gave no exact position. The first investigations underwater also failed to provide sufficient certainty.
New measuring techniques changed that. Sonar and other seabed scans revealed unusual structures. Diving investigations remained difficult because almost nothing could be seen underwater, but the combination of measurements, finds and location matched what researchers expected from a medieval stronghold at this site.
In August 2025, the researchers announced that they convincingly associated the location with the vanished castle of Wijdenes. Not every question has been answered, but the connection between the remains, the historical sources and the coastal setting is strong.
What remains today
From the dyke, you see no walls, moats or changes in elevation. The castle site lies out of reach on the bottom of the Markermeer. Yet the location is not empty. The present shoreline reveals how much land has disappeared here since the Middle Ages.
From the Omringdijk, imagine a strip of land extending further into the water. There stood a castle for less than fifteen years, before it was surrendered and ultimately dismantled. What remains is not a ruin above ground, but a place where political history and a changing landscape literally overlap.