The hillfort in Bonikowo is an example of a small fortified settlement controlled by one of the many tribal chiefs who ruled on the south-western frontier of Greater Poland. Its construction required massive amounts of work and materials, yet after a mere 150 years of existence, the hillfort, in a way, fell victim to changes in the organisational and settlement structure of the early Piast state, which included the annihilation of the social structures of the conquered tribal communities. The fort, today levelled to a significant degree, was originally a powerful settlement; the hillfort’s system of earthen and wooden reinforcements is among the best solutions of the contemporary fortification art. The scientific value of this site is enhanced by the fact that another, earlier settlement, dating back to the very beginning of the Middle Ages, had also existed here.

Location and description

The hillfort is situated on a sandy mound among meadows, in a marshy, lowland area which used to remain waterlogged due to the presence of the Obra River backwaters, currently mostly dry owing to the construction of the Mosiński Canal in the late 19th century. It is located approximately 2 kilometres west of the village of Bonikowo and about 200 metres west of the Mosiński Canal.

The hillfort consists of a number of sections. The round hollow no. 1, having a diameter of approx. 25 metres, is enclosed with an earthen rampart (rampart no. 1), about 2 metres high, now partially destroyed. On the south-east side, the hollow is adjoined by other elements: hollow no. 2 (the oldest fortified part), surrounded by rampart no. 2, currently 1.5 metres high, and further hollow no. 3, nearly rectangular in shape, enclosed with rampart no. 3, about 2 metres high, as well as a lower, crescent-shaped outer rampart. The entire hillfort is surrounded by a moat, about 8 metres wide. The total length of the hillfort is approximately 180 metres, its maximum width being approx. 100 metres. Its total surface area (including moats) is about 2.5 hecrates.

The hillfort is not used today and it is overgrown with thick grasses.

History

Prior to the establishment of the hillfort, an open settlement existed here between the 6th and 8th centuries. In the first half of the 9th century, it was replaced with a fortified settlement, which stood here until the second half of the 10th century or perhaps until the late 10th/early 11th century. It is suspected that this complex structure was not built in a single stage but was gradually extended over time. Rampart no. 2 is the oldest part of the hillfort. Dendrochronological studies indicate that it was built of timber from trees felled after 815 and after 826. It was most likely in a later period that the ramparts surrounding a separate little hillfort (hollow no. 1) were built and the original hillfort was extended through the construction of the new rampart no. 3.

Condition and results of archaeological research

The Bonikowo hillfort has been the subject of scientific interest and numerous site inspections since the late 19th century.

Excavations were carried out in the years 1951-53. They were led by Zofia Hołowińska under the supervision of professor Witold Hensel. The next research was performed under the direction of professor Zofia Hilczer in the years 1958-1959. Both defensive and residential structures were unearthed during the excavations. The hillfort buildings are half-earth lodges with wattle-and-daub walls and wooden floors, accompanied by storage pits. The individual ramparts were made using different construction techniques. The oldest rampart (no. 2), about 13 metres wide, is a rampart with an earthen and clay core. Its inner and outer surfaces were covered with unidentified wooden structures. There was a stone structure on the top. The core of rampart no. 1 has been a wooden and earthen structure in the form of an irregular frame immersed in sand, with stone reinforcements on the inside and a stone sheathing on the outside. The rampart was topped with an extensive wooden structure. The core of rampart no. 3 was built around a frame next to which sand-filled wooden boxes were positioned. It was flanked by a low outer rampart (the so-called pre-rampart) built around a wooden frame.

During the research, an ample collection of ceramic artefacts and so-called isolated artifacts was found at the site; they were made of bone (e.g. awls and fragments of covering materials), stone (e.g. quern-stones), and metal (e.g. knives, fibules, pliers, and a spur).

In the 1990s, wood samples were collected from the ramparts in order to date the site as part of a project aimed at verifying the age of selected fortified settlements on the basis of dendrochronological indications. The analysis of the samples confirmed the earlier archaeological dating results. In order to verify the archaeological findings pertaining to the spatial structure of this archaeological site, lithological (granulometry) and geochemical analyses (the latter concerning e.g. the phosphor content) were also performed, once again supporting and confirming the earlier conclusions.

The site is accessible.

compiled by Elżbieta Wyrwińska, Regional Branch of the National Heritage Board of Poland in Poznan, 25-08-2014.

Bibliography

• Kara M., Stan badań dendrochronologicznych wczesnośredniowiecznych grodzisk z terenu Wielkopolski, [w:] Buko A., Świechowski Z. (red.), Osadnictwo i architektura ziem polskich w dobie zjazdu gnieźnieńskiego, Warszawa 2000, s. 55-68.
• Hensel. W, Studia i materiały do osadnictwa Wielkopolski wczesnohistorycznej, t. 1, 1950, s. 78-79.
• Hildebrandt-Radke I., Główne etapy zasiedlenia i rozbudowy grodziska w Bonikowie (Wielkopolska) w świetle badań litologicznych i geochemicznych, Landform Analysis, vol. 16, 2011, s. 77-80.
• Hołowińska Z., Wczesnośredniowieczne grodzisko w Bonikowie w powiecie kościańskim. Wyniki badań z lat 1951-1953, Poznań 1956.
• Hilczerówna Z., Gród z początków wczesnego średniowiecza w Bonikowie, pow. Kościan, Sprawozdania Wydziału Nauk Społecznych PAN, 3, 1960, s. 59-65.
• Hilczerówna Z., Dorzecze górnej i środkowej Obry od VI do początków XI wieku, Wrocław 1967.