Biskupin, a village located on Lake Biskupińskie, in today’s Kuyavian-Pomeranian Voivodeship, became known in the 1930s, thanks to the discovery of a prehistoric stronghold. It was built in the 8th century BC on a lake island and was inhabited until the 6th century BC. In the same place, in the 5th and 4th centuries BC an open settlement existed. After its abandonment, the island was partially flooded by the lake’s waters, partially covered with thick layers of silt and peat, hiding the remains of buildings for hundreds of years. Changes in the water level turned the area into a peninsula.

In 1932, the Gąsawka river flowing through Lake Biskupin was regulated, which resulted in the lowering of its waters and the discovery of parts of the settlement. Before that, local peasants had found bronze objects, fragments of pottery and tools in the fields, about which their children informed the local teacher, Walenty Szwajcer. He reported the information about the finds and about, as he believed, thousand-year-old roofs protruding from the water to Professor Józef Kostrzewski, an archaeologist from the University of Poznań,.

The research began almost immediately, initially with a very modest budget of 140 zloty. For comparison, the average male worker earned around 102-103 zloty a month, a female worker around 50 zloty, and an overground worker in a hard coal mine around 193 zloty. Soon, however, the budget of archaeologists increased many times, reaching the amount of 30,000 zloty within a few years. This was mainly due to the meaning of the find, which had no equivalent in Europe, due to the time of its origin. The vivid information and advertising campaign conducted by Prof. J. Kostrzewski and his student, Dr Zdzisław Rajewski also contributed to the fame of the spot.

Archaeologists who earlier lived in rented tents during the first works and removed water from the trenches with a manual pump later formed a large team. It consisted of a dozen scholars, several dozen blue-collar workers (who once happened to be in a short strike), a balloon for aerial photography, and even divers from the Polish Navy. The large scale of the work was caused by the fact that, due to the very good condition of large fragments of the settlement, archaeologists wanted to use the opportunity to get to know the conditions of everyday life. The research confirmed the belief that had been firstly announced in 1933 by Prof. J. Kostrzewski that Biskupin should be attributed to the Lusatian culture. His results have not changed to this day, although the dating of Biskupin is now different. Currently, scientists believe that a stronghold in this place was established at the turn of the Bronze Age and the Iron Age.

During the research, innovative solutions were used, establishing cooperation with various specialists (including geologists, dendrologists, architects, palaeozoologists) in order to correctly date the find, and determine the periods of water level change in the lake, reconstruct the appearance of the settlement, etc. Data from the interwar period show sometimes very interesting results. For example, the diet of the inhabitants of Biskupin amused the scientists. On the basis of the preserved remains, it was found that they ate farm animals, probably also dogs, but why were almost no fish bones found in the area near the water?

The period of World War II turned out to be a very difficult time in the history of Biskupin. Professor J. Kostrzewski who was wanted by the Germans from the beginning of the war, fortunately, managed to flee the so-called Reichsgau Wartheland, incorporated into Germany. He spent the war hiding under a false name in the vicinity of Tarnów and Nisko. Biskupin became a place of interest for a special SS unit (SS-Forschungseinrichtung »Ahnenerbe« (Literally meaning: SS Research Institute “Ancestral Heritage”), which set itself the goal of proving that the stronghold in Biskupin was built by one of the Germanic tribes. However, the research under the supervision of Hauptsturmführer, Professor Hans Schleif did not confirm this thesis. Therefore, the work was stopped, the area was covered with sand, and the final report was prepared in a way excluding the possibility of the participation of the Slavs (for the benefit of the Illyrian people) in the creation of the settlement. It was written in a typical pseudoscientific German style from World War II time:

The stronghold, like other North Illyrian strongholds, fell. We know, first of all, that it was destroyed by fire. The East Teutons remained the victors, but as a rule they did not make use of the Illyrian strongholds. After the struggle of their youthful people, they remained the undisputed masters of the country (quote from the report from: K. Reichenbach, Biskupin – Ur (slawen) statt. Prähistorische Archäologie als deutsch-polnische Beziehungsgeschichte“. Mitropa. Jahresheft des Leibnitz-Instituts für Europa “2017, par. 10-15, pp. 13).

After the end of World War II, the governing communist authorities tried to use Biskupin for its propaganda. The stronghold was presented as a double victim of the Germanic Drang nach Osten (Drive to the East); According to this narrative, the first attack was to take place in prehistoric times, the second – during the war that had just ended. Information was spread to the press that the excavations had been buried for destruction. Paradoxically, however, sand contributed to the preservation of prehistoric artefacts. It is also worth noting that in the first post-war reports from Biskupin (works were resumed already in May 1946) there is no information about intentional damage. However, there are reports of deliberate neglect of securing the site resulting in damage of the interwar reconstruction.

Biskupin remains one of the most important archaeological discoveries in Europe to this day.