Mieszko I of Poland Abraham ben Jacob. According to him, Mieszko I had fought against the Weltaba tribe, commonly identified with the Veleti. Wichmann the Younger, a Saxon nobleman who was then a leader of a band of Polabian Slavs, defeated Mieszko twice, and around 963 a brother of Mieszko, whose name is unknown, was killed in the fighting. The frontiers at the mouth of the Oder River were also desired by the German margraves. In addition, the Veleti Bohemia, which at that time possessed Silesia and Lesser Poland regions, constituted a danger for the young state of the Polans. The chronicle of Thietmar
Mieszko II the Fat and was succeeded by his son Henry II the Pious, who also assumed the regency over Opole-Racibórz. Shortly after, Mieszko II began to claim the government of their lands. It is unknown exactly when Mieszko II took over the rule over Opole-Racibórz, but this has been probably in late 1238 or early 1239 (who is more likely). One of the first politic decisions of Mieszko II was his marriage with Judith (b. 1222/25 – d. 4 December 1257/65?), daughter of Duke Konrad I of Masovia, who gave to the Duke of Opole-Racibórz greater autonomy in his rule. Mieszko II's mother