XVIII. Von der Osten men pay homage to Santok Casimir the Great
After the end of the Askan dynasty in 1320, the Santok castle became the subject of rivalry between significant March families. In unclear circumstances, the castle was taken over by the von der Osten family. On July 22, 1365 in Kraków, Dobrogost von der Osten from Drzenia (Drezdenko) – together with his brothers Arnold, Ulryk and Bertold – surrendered the Santok and Drzeń castles and their belongings to the Crown of the Polish Kingdom, accepting them at the same time as a fief from Casimir the Great. It seems probable that the Santok castle mentioned in the document also included a town located on the northern bank of the Warta River. The surprising decision of the von der Osten brothers probably resulted from the desire to protect their possessions from the powerful Brandenburg families: Jagów, Uchtenhagen and Wedel.
Until 1370, a Polish crew was stationed in the castle in Santok. Then it was taken over by the von Wedel family and remained in their hands until 1385.
Loss of importance of the Santok hillfort (from the second half of the 13th to the 15th century)
The importance of Santok in the middle of the 13th century was still great. There were probably two hillforts there: a smaller one – serving as a prince’s residence – and a larger one, inhabited by the crew, peasants and craftsmen. In addition, the preposit of St. Andrew. However, the hillfort between the Piasts and the Brandenburgers – sealed by the marriage of a Polish princess and a Brandenburg prince – did not last long. From 1265, the battles for Santok began, which were conducted with varying success for both sides. After the murder of the Polish king Przemysł II in 1296, the scales of victory turned in favour of the Brandenburgers. It was then that a long period of Brandenburg history began, interrupted only by half a century of Teutonic rule (1402–1454) and two short episodes of Polish rule (1365–1370 and 1433–1437). It was a time of decline for Santok. The „formerly very great hillfort” has been reduced to the role of a border guard.