Foundations of the walls

Foundations of the "tower"

Remnants of the forge

Lower levels of the forge

Remains of a hut

During ten years of excavations the following was clarified:

A. Questions of chronology and culture:

• Grzybowo is a multicultural site, inhabited with periodic breaks repeatedly from the Mesolithic Age until recently. The Mesolithic and Neolithic are represented by some number of flint tools, and a large amount of flint byproducts and rejects. Also a few Neolithic pottery sherds were found. The Roman Period has been confirmed by fragment of a bronze fibula (sort of a safety pin) and a multicolored glass bead. Unfortunately, the evidence of a pre-mediaeval inhabitancy occurred only in a form of secondary deposits. The older artifacts were mixed up and re-deposited with the early mediaeval materials.
• The occupation of the site in the Middle Ages has been confirmed dendrochronologically for the year 915. The settlement flourished in the first half of the tenth century, and then, due to the loss of its status, gradually declined.

B. History and role of the fortress:

It is still difficult to establish both - the history of its development and the role which it fulfilled during the beginning of the Piast's empire. It had to be very important since it is one of the largest at the time. A whole network of smaller earthworks was built by the first rulers to assure control of the various clans, who were forced to join together and form one state ruled by the Piast family. History starts with Mieszko The First in 966 but it seems that either his father or more likely his grandfather were already powerful rulers. The building of the Grzybowo fortress required an enormous effort. In addition to the ramparts visible today, we found inside the earthworks wooden foundations of a large structure, which may have been an additional inner fortification. Its walls were taken down probably in the tenth century but the remains are well preserved at the level of 2 meters below the surface. They allowed an exact dendrochronological dating. It was found that the construction was done in three phases around the year 930. The rust construction was reinforced with wooden hooks, which were found well preserved. The wall was built as a rust construction fortified with hooks at lower levels. The outer wall was 630 meters long and enclosed an area of 3.4 hectares and was 20 meters wide and up to 16 meters high. A wooden skeleton was filled with clay and earth, which remained on site and reaches today a height of 9 meters. It is estimated that about 3.5 million beams made mainly from oak representing 62 thousand cubic meters and 83 thousand cubic meters of earth were used. An encircling moat was 20 meters wide.

Two gates lead to the fortress (see the Fig 1 showing the reconstruction of the walls on page "Fortified settlement from the tenth century in Grzybowo") Initial excavations were started in the back of the eastern one. We found there an accumulation of stones, which formed foundations of a building, probably a defense tower. This site requires further investigations.

We concentrated our efforts on the investigation of the ramparts and only a few buildings inside the fortress were excavated. We found a cowshed with well preserved manure and a forge near the south western ramparts. Several huts could be identified by remains of their hearths.