At the beginning of the 14th century, the inhabitants of Gdańsk used the mill at St. Adalberts, therefore it is supposed that no grain mill operated in Gdańsk at that time. The Great Mill was built by the Teutonic Knights around the mid-fourteenth century on the artificial island of the Radunia Canal, near a tannery, fulling mill, copper smithy, sawmill, oil mill, grinding plant and several other smaller grain mills. The first record of it appeared in 1365, but already before 1338 an artificial mill canal was dug from the vicinity of Pruszcz Gdański, passing through the Old Town and flowing into the Vistula. Before 1356, the Teutonic Knights dug a new mill canal, which, running from Orunia, took over the waters of the Siedlce Stream.
In 1391, the Great Mill burned down, but due to its importance it was soon rebuilt. Special fees, imposed by the Teutonic Knights on service recipients, significantly contributed to this. Around 1400, another important watermill was built, called the Small Mill, also located on the Radunia Canal in the Old Town. It served mainly as a granary for products from the Great Mill located on the opposite side of the street.
In 1454, the Great Mill was captured by the inhabitants of Gdańsk, belonging to the anti-Teutonic conspiracy, which initiated the uprising against the supremacy of the Teutonic Order. After the Thirteen Years War, which was victorious for Poland, king Kazimierz Jagiellończyk handed over the mill to the inhabitants of Gdańsk. Until 1939, it remained in use and produced up to 200 tons of flour per day. During the Second World War it was partially destroyed. In 2016, it was donated to the needs of the Amber Museum.
The Great Mill was one of the largest medieval grain mills in Europe. It was 26 meters high and 41 meters long. Situated on an island created for this purpose on the Radunia canal, it was surrounded on both sides by water, which allowed to double the number of mill wheels, and thus increase efficiency. The mill initially had 12 and then 18 bucket wheels with a diameter of 5 meters. As a result, the processing amounted to 3.5 to 4 thousand lasts of grain per year, which was about 43 m3 per day, assuming work on all days of the week, except Sundays.
The two lower floors of the Great Mill were occupied by mill wheels, while the six upper floors were intended for a warehouse. In the annex to the east, you could bake bread, then sold, among others, on the Bread Bridge at the Old Town Hall. The only decorative elements were manifested in the fragmentation of both gables by narrow, pointed-arched recesses housing windows and in the crowning of the western gable with three brick pinnacles of a very simple form. Around the Great Mill there were also many other buildings, such as stables, bread stalls and the mill manager’s house.
The Small Mill was erected above the waters of the canal as a simple ridge structure with two triangular gables supporting a gable roof. One of the gable walls was decorated with narrow, elongated pointed-arched recesses with windows, under which a semicircular arcade was placed for the flowing waters of the channel.
The two Gothic Gdańsk mills, preserved to this day, despite the early modern transformations and depriving them of their original function, are one of the most important monuments of early technology in Poland. Inside the Great Mill, today there is the Amber Museum, while the Small Mill is occupied by offices, so its interior is not open to the public. In the Great Mill, apart from precious stones, you can see two fragments of a stone burr, which was used to grind grain into flour.
Friedrich J., Gdańskie zabytki architektury do końca XVIII wieku, Gdańsk 1997.
Paner H., Rozwój przestrzenny wczesnośredniowiecznego Gdańska w świetle źródeł archeologicznych, “Archaeologia Historica Polona”, tom 23, 2015.