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 Casimir II's eldest son, Leszek the White. Both sides clashed in the bloody Battle of Mozgawa (Mozgawą) near Jędrzejów (13 September 1195), where Mieszko III was seriously injured and his son Bolesław of Kuyavia died. The Silesian troops, led by Mieszko and Jarosław, arrived to the battlefield too late, soon after Mieszko III withdrew to Kalisz. Despite the forces of the Count palatine Goworek who also arrived to help Leszek's troops, the Silesians obtained a great victory; however, because Mieszko III wasn't present, this victory brought to them only benefits in terms of prestige (not counting the ransoms obtained by