Researchers discover medieval church lost to sea in 1362

A joint scientific project has located the sunken church of Rungholt in the North Frisian Wadden Sea in Germany. It is believed that the church and the rest of Rungholt were drowned in a storm surge in 1362.

Rungholt was an important port in the Middle Ages, with a population of up to 3,000 people. However, it was one of several places destroyed on the night of 15-16 January 1362, during Saint Marcellus’s flood or Grote Mandrenke (‘Great Drowning of Men’) took place. This was an immense storm that struck parts of Great Britain, The Netherlands, Germany and Denmark, killing at least 25,000 people and drastically altering the coastline in the region.


For over a hundred years researchers have been searching for Rungholt. Using a combination of geoscientific and archaeological methods, researchers from Kiel University (CAU), Johannes Gutenberg University Mainz (JGU), the Center for Baltic and Scandinavian Archaeology (ZBSA), and the State Archaeology Department Schleswig-Holstein (ALSH), both in Schleswig, have now succeeded in locating the site of its church.

The researchers use sediment cores to record settlement remains and to reconstruct landscape evolution at selected sites on the tidal flats. (photo/©: Justus Lemm)

In May 2023, a previously unknown two-kilometer-long chain of medieval terps, which are artificial settlement mounds, was recorded by geophysical prospection near Hallig Südfall. One of these terps shows structures that can undoubtedly be interpreted as the foundations of a church 40 meters to 15 meters in size. First corings and excavations have provided initial insights into the structure and foundations of the sacred building.


“The find thus joins the ranks of the large churches of North Frisia,” stated Dr. Bente Sven Majchczack, archaeologist in the ROOTS Cluster of Excellence at Kiel University. Dr Ruth Blankenfeldt, an archaeologist at ZBSA, added: “The special feature of the find lies in the significance of the church as the center of a settlement structure, which in its size must be interpreted as a parish with superordinate function.”

So far, the finds in the area investigated, which covers more than ten square kilometers, include 54 terps, systematic drainage systems, a sea dike with a tidal gate harbour as well as two sites of smaller churches – and now also a large main church. The settlement area found must therefore be regarded as one of the historically reported main sites of the medieval administrative district of Edomsharde.

A lightweight survey vehicle provides large-scale magnetic mapping of cultural traces hidden beneath the present-day tidal flat surface. (photo/©: Dirk Bienen-Scholt)

In addition to the unique archival character that the mudflats have for the reconstruction of Rungholt’s cultural landscape, the project results of recent years also show the extreme endangerment of the cultural traces that are over 600 years old. “Around Hallig Südfall and in other mudflats, the medieval settlement remains are already heavily eroded and often only detectable as negative imprints. This is also very evident around the church’s location, so we urgently need to intensify research here,” emphasized Dr. Hanna Hadler of the Institute of Geography at Mainz University.

The key to the success of the work lies in a close interdisciplinary collaboration. “Settlement remains hidden under the mudflats are first localized and mapped over a wide area using various geophysical methods such as magnetic gradiometry, electromagnetic induction, and seismics,” explained Dr. Dennis Wilken, a geophysicist at Kiel University.


Top Image: A special metal frame allows archaeological excavations of one square meter in the tidal flats. The finds are excavated and documented during low tide. (photo/©: Ruth Blankenfeldt)