Mieszko I of Poland by him. As Widukind of Corvey wrote, Mieszko ruled over the tribe called the "Licicaviki", now commonly identified with the Polabian Lubusz Land. Having the control over those more western (in respect to the original homeland of the Polans) tribes, Mieszko had entered the German sphere of influence. In 963 the German Margrave Gero conquered territories occupied by the Polabian Lusatian and Słupian tribes, and as a result came into direct contact with the Polish state. At the same time (about 960) Mieszko I began his expansion against the Velunzani and Lutici tribes. The war was recorded by the chronicler
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