Wczesnośredniowieczne grodzisko w Skrwilnie (stanowisko 1), w świetle badań przeprowadzonych w 2015 roku

The excavation work carried out within the early mediaeval stronghold in Skrwilno (site 1) was one of the tasks carried out as part of a research project financed by the National Program for the Development of Humanities. So far, the most spectacular discoveries related to the recognition of the Maidan zone and the rampart of the stronghold, as well as the part directly adjacent to the early mediaeval stronghold, were made in the 1960s, under the supervision of Jadwiga Chudziakowa. The main assumption of the field research carried out in 2015 was, inter alia, verification of the chronology of cultural layers lying on the stronghold, including relics of residential buildings and elements of fortifications (palisade and embankment structure).Grodzisko (local name Okop Szwedzki) is situated on the very shore ofSkrwileńskie Lake. The first mentions of the object in question come from the 1880s. The facility is now located on a small, sandy clump – the original island which, due to the rapid drying out of Skrwileńskie Lake and the Skrwa River connected with it, is now situated in the coastal (north-western) part of the reservoir. The object is in the shape of a regular oval measuring 90 × 56 m (measured on the outer base of the embankment) and covers an area of about 40 ares.The work carried out in 2015 focused on three research excavations, within which the infrastructure of the inner part of the square, the structure of the embankment, as well as the zone directly adjacent to Skrwileńskie Lake, in the form of a fragment of a bridge with a stone fortification and remains of a palisade, were identified. From the preserved wooden elements, samples were taken for dendrochronological and radiocarbon analyzes. During the field work, six cultural objects were documented (objects 1–3, 3a, 3b, 4), all of them were registered within the area of the stronghold (excavation 1/15). During the excavations carried out in 2015, a total of 423 fragments of pottery vessels were obtained, representing: the early Iron Age (2 fragments), the early Middle Ages (418 fragments) and the late Middle Ages (3 fragments). Among the early mediaeval vessels there were hand-made, fully rolled (GT V) items with forms characteristic of both Kujawy (2nd half of the 11th century) and the Chełmno Land, including the Lower Drwęca and Kałdus basins, where analogous specimens appear in the cultural layers combined withthe VI–VII settlement phase of the hillfort (dated from the second to the fourth quarter of the 11th century).By comparing the results of the stratigraphic and typological-comparativeanalysis of movable source materials, especially vascular ceramics, with dendrochronological data, the oldest stage of use of this site in the early Middle Ages can be related to the second half of the 11th century and should be combined with the elements of the internal buildings of the hillfort (object 3b), with a palisade and with the preserved elements of the wooden and earth embankment erected in a sandwich structure. The next stage of settlement activity should be connected with the first half of the 12th century, when the burnt hillfort was rebuilt (objects 1 and 3a – the older level; objects 2, 3 and 4 – the younger level). For this stage, dendro dates were obtained for three oak piles (1120–1125 AD; Valid 2016).In 2015, the presence of hand-glued, partially rolled materials, documented during research in the 1960s, was not confirmed. However, this does not rule out the assumption that the beginning of the functioning of the facility in Skrwilno (castle complex?). Can be referred to the end of the 9th–beginning of the 10th century. Contrary to Kujawy and the Chełmno Land, the settlement of the Dobrzyń Land during this period was, however, a relatively incidental initiative. The subsequent stages of the development of the Skrvilean center should be related to the 11th century, when the castellan organization was formed, which involved the reorganization of the spatial structures of settlement and the emergence of new castle centers. Around the second half of the 11th century, the so far small building was surrounded by a huge wooden and earth embankment built in a sandwich structure, and the usable space of the courtyard was built up with houses and elements of communication infrastructure. It can be assumed with high probability that the stronghold in Skrwilno, due to its peripheral location and powerful defensive assumptions, played a remarkably guarding role in the Piast castle system. After partial destruction, the Skrwilno facility was rebuilt again in a relatively short time (around 1120–1125 AD). However, its role in the state defense system has probably decreased significantly over time. In such a situation, the tasks of the castle in Skrwilno could be taken over by other objects, e.g. the castle in Starorypin.W artykule zaprezentowano wyniki badań archeologicznych przeprowadzonych na wczesnośredniowiecznym grodzisku w Skrwilnie (stanowisko 1) w 2015 roku. W trakcie prac rozpoznano relikty drewniano-ziemnego wału, elementy wczesnośredniowiecznej infrastruktury związanej z zabudową majdanu oraz strefą przylegającą bezpośrednio do Jeziora Skrwileńskiego. Pozyskany materiał ceramiczny reprezentuje formy charakterystyczne dla Kujaw i ziemi chełmińskiej w XI wieku