Mieszko I of Poland Catholicism, Mieszko I included his Polish state in the European community of Western (Latin) Rite states, i.e. Roman Catholic states. Consequently, neither the Holy Roman Empire nor any other Catholic country could invade Poland for the purpose of Christianizing the region, and Poland could now assert its right to be treated like other Christian states. The baptism also started the spread of the Latin culture into Poland, with the first literate and educated churchmen-advisers joining Mieszko's court. The missionary bishopric started by Jordan in 968 used the Latin liturgy and was directly subordinate to the Papacy. Churches were being built
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