During Polish rule of the area in the late 10th century, the chronicle of Thietmar of Merseburg (975–1018) mentions "salsa Cholbergiensis" as the see of the Bishopric of Kołobrzeg, set up during the Congress of Gniezno in 1000 and placed under the Archdiocese of Gniezno. The congress was organized by Polish duke Bolesław Chrobry and Holy Roman Emperor Otto III, and also led to the establishment of bishoprics in Kraków and Wrocław, connecting the territories of the Polish state. It was an important event not only in religious, but also political dimension in the history of the early Polish state, as it unified and organized medieval Polish territories.