The castellan’s settlement was established during the time of peak expansion of Poland into Prussian lands. It constituted a strategic site considering the plans of the Piast monarchy and a starting point for the Christianising expeditions undertaken by Bolesław the Wrymouth and later by his sons.

Location and description

The hillfort is situated roughly 12 km north-east of Brodnica, in the northernmost part of the long peninsula cutting into the valley of the Brynica and Drwęca rivers.

The hillfort is a two-component feature and has a surface area of 1 ha. The first component of the hillfort, which served as the actual hillfort, has the shape of an ellipse which has been slightly flattened from the south. Its total area is 3900 m2. The highest point of the surrounding rampart is roughly 5-6 m above the level of the land around the hillfort. Its width at the base is roughly 25 m. The inner yard, which is located within the first component, has a surface area of roughly 1500 m2. It is a sunken area with a slight elevation in the middle.

The first component is separated from the next one, which adjoins it from the south, by a trough-shaped depression, which is likely a remnant of a moat. The second component of the hillfort measures roughly 7,000 m2 and is shaped like a regular rectangle. Its dimensions measured at the base are 100 m × 70 m. The surrounding rampart of similar size, whose measurements are similar to those of the rampart surrounding the first component, is shaped like a horseshoe and open to the north. The inner yard measures roughly 3,500 m2 and is a sunken area with a slight elevation in the middle. To the south of the hillfort, there is a small through-shaped land depression. This is a trace of the moat which separated the hillfort from the ancillary settlement. To the north of the hillfort, there is a triangular land elevation separated from the feature be a moat which is 15 m wide. It is possible that a bastion was located in this spot.

The hillfort has been preserved in a relatively good condition.

History

The hillfort was used in three distinct settlement phases. Around the mid-11th century, an open settlement was established on the elevation. In the second half of the 11th century or at the turn of the 12th century, a major part thereof was used to built a two-compound fortress as a one-time establishment. From the time of its construction, the structure was destroyed multiple times. The first damage to the hillfort fortifications are dated at the mid 11th century, with subsequent damage dating likely to the late 12th century.

It is known that the hillfort was also in use in the 13th century. Most likely, the hillfort in Grążawy should be equated with castrum Zvytinense, which is mentioned in written sources from the 13th century and was the property of the bishops of Płock. The fact that the hillfort was used in the 15th-16th century is evidenced in the discovery of pottery fragments within its area.

Condition and results of archaeological research

The first surface surveys were carried out in the years 1895-1897 on behalf of the Provincial Museum in Gdańsk.

In 1969, archaeological works were carried out by employees of the Department of Archaeology of the Nicolaus Copernicus University in Toruń and the Grudziądz Museum.

The research focused mainly on the area of the ancillary settlement. A total of 12 research excavations were made, each having the dimensions of 4.5 m × 4.5 m. Within the hillfort, there were two research excavations measuring 5 m × 5 m. They were situated in the central part of the inner yards of both hillfort components. In 1990, a single trial excavation was made, measuring 2 m × 2 m and situated at the junction between the rampart and the inner yard of the second feature component. A total of 54 m2 of the hillfort area was examined. Further research was conducted on behalf of the Brodnica Museum in 1996 and in the years 2002-2005. It was then that the stratigraphic layout of both components of the hillfort was determined, examination of the ancillary settlement was continued and a bridge route was identified.

Based on surveys of the layers found in the inner yard of the first component part of the hillfort, it was determined that this part was a single-phase settlement while the other component was a two-phase settlement. The first phase was connected with the early Middle Ages while the next one with the later Middle Ages and the early modern period.

In the south-eastern part of the first hillfort component, there were remnants of the sandwich structure of the rampart, traces of charred fortifications, remnants of a wooden house and traces of a destroyed masonry oven. Inside the fill of the residential structure, there were numerous pottery fragments and post-consumption remains of animal bones. In the footwall of this fill, there were remains of an incomplete human skeleton, which was not arranged in an anatomical way. It is possible that the skeleton belongs to one of the hillfort inhabitants and was crushed by the collapsing building walls and rampart fortifications. In the southern part of the inner yard of the second component, an abundance of historical and osteological material was discovered.

Archaeological research has found that the number of plants related to human agricultural activity in Grążawy increased in the early Middle Ages. The pottery fragments found within the hillfort and the ancillary settlement are remnants of wholly-rounded spherical, S-shaped and double cone-like vessels, with a heavily leaning edge and quite common ornamentation in the form of surrounding grooves or comb punctures, as well as zonal ornamentation.

Noteworthy isolated artefacts include the four specimens of iron arrowheads, three specimens of iron crampons for walking on ice as well as several partially-preserved knives and nail fragments, four specimens of clay spindle whorls and a glass bead.

Within the ancillary settlement, remnants of storage and waste pits, remnants of hearths, ovens and buildings were discovered. Other discoveries included a set of pottery dated at the period from the 10th century to the first half of the 13th century, several specimens of goblets on a hollow stem, two specimens of iron knives, a horse bit, an iron sickle, a wedge and iron chisel as well as iron crampons for walking on ice.

The hillfort is accessible all year round.

Prepared by Paweł Baraszkiewicz, National Heritage Board of Poland, Regional Branch in Toruń, 15-12-2016

Bibliography

• Grążawski K., Kasztelania świecka i michałowska. Studia nad kształtowaniem się struktur państwa piastowskiego na pograniczu polsko-pruskim, Włocławek 2005
• Kola A., Grążawy, [in:] Wczesnośredniowieczne grodziska ziemi chełmińskiej. Katalog źródeł, Toruń 1994, pp. 56-59