First half of 10th century – Construction of a stronghold on Castle Hill -
A small hill located at the Olza and a ford nearby offered perfect conditions for the establishment of a fortified settlement. Probably the destruction of a fort of the Golensizi in the area of village Kocobędz/Chotěbuz, called Old Cieszyn, today lying within the borders of Český Těšín, brought the survivors’ paid attention to the nearby hill near the Olza. Supposedly, Castle Hill in Cieszyn was initially a base for those who were trying to rebuilt the fort, but over time, when the efforts to rebuild the fort were abandoned, it became the main settlement for its inhabitants. It is certain that already in the 10th century, a fortified town existed on Castle Hill in Cieszyn.