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, Duke of Cieszyn the church. Thanks to him, the construction was completed of the Dominican convent at Oświęcim (shortly after 1283). Also, he financially assisted the monastery of Czarnowąsy near Opole and in the Dominican of Cieszyn. Mieszko's exact date of death is unknown. Diplomatic sources suggest that he died in 1314 or in the first half of 1315, before 27 June. He was probably buried in the Dominican church in Cieszyn. In 1931 the Polish painter and sculptor Jan Raszka made a sculpture of Mieszko I in Cieszyn. According to some sources, Mieszko's wife died around 1303, but her name is unknown.