By the early 12th century, the Archbishoprics of Bremen, Magdeburg and Gniezno sought the conversion of the pagan Slavs to Christianity through peaceful means: notable missionaries included Vicelin, Norbert of Xanten, and Otto of Bamberg (sent to Pomerania by Bolesław III Wrymouth of Poland). Lacking support from the Salian dynasty of the Holy Roman Empire, secular Saxon princes seeking Slavic territory found themselves in a military stalemate with their adversaries. Christians, especially Saxons from Holstein, and pagans raided each other across the Limes Saxonicus, usually for tribute.