Mieszko I of Poland Pomerania, eventually conquering it up to the vicinity of the lower Oder river. During the last years of his life, he fought the Bohemian state, winning Silesia and probably Lesser Poland. Mieszko I's alliance with the Czech prince, Boleslaus I the Cruel, strengthened by his marriage in 965 to the Czech Přemyslid princess Dobrawa, and his baptism in 966 put him and his country in the cultural sphere of Western Christianity. Apart from the great conquests accomplished during his reign (which proved to be fundamental for the future of Poland) Mieszko I was renowned for his internal reforms, aimed at
Mieszko the Younger point, Mieszko III decided to give the district of Kalisz to his youngest son and namesake, as his own Duchy. Mieszko the Younger died on 2 August 1193. He was buried in the crypt founded by his father in the Cathedral of St. Paul the Apostle in Kalisz. Tombstones of Mieszko the Younger and Mieszko III were found during archaeological excavations during 1958–1960. For unknown reasons, Mieszko never married or had children. On his death, Mieszko III give Kalisz to his eldest son Odon. Mieszko the Younger Mieszko the Younger (also known as of Kalisz) () (between 1160 and 1165