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 I Tanglefoot to both Mieszko (who received the towns of Racibórz and Cieszyn) and Jarosław (who received Opole). In 1177 Mieszko supported his uncle and namesake Mieszko III the Old when he had to fight to maintain his rule over the Duchy of Kraków; this renewed again the disputes between him and Bolesław I the Tall, who wished to obtain the Duchy and with this the Seniorate. However, Bolesław suffered an unexpected defeat by Mieszko and his own son Jarosław, who distracted him to advance over Kraków; in his place was his younger uncle and ally, Casimir II the Just, who captured