Mieszko I of Poland one version of the legend of St. Wojciech it is written that Mieszko I had his daughter married to a Pomeranian prince, who previously voluntarily "was washed with the holy water of the baptism" in Poland. The above information, as well as the fact that Bolesław lost Western Pomerania, suggest that the region was not truly incorporated into the Polish state, but only became a fief. This conjecture seems to be confirmed in the introduction of the first volume of the chronicles of Gallus Anonymus concerning the Pomeranians: "Although often the leaders of the forces defeated by the Polish duke
Mieszko I, Duke of Cieszyn The Obituary of the Church of St. Vincent in Wrocław showed the existence of a certain "Grzymisława, Duchess of Opole" ("Grimizlaua ducissa Opuliensis") who was buried there around 13 September 1286. Her parentage is also unknown, but her name suggests a Russian origin, probably member of the Rurikids. Her title suggests that she may have been the wife of Mieszko I or the first wife of Bolko I (Mieszko I's brother), or maybe a completely different person. Also, the exact date of their marriage was uncertain, but after a further reconstructions of their children's birth dates, was placed between 1275