How did the Polish become Catholic?
The baptismal mission which began in the two major cities of Gniezno and Poznań with the baptism of Mieszko and his court spread throughout the country. By the 13th century Roman Catholicism had become the dominant religion throughout Poland. …
Who lived in Poland before the Slavs?
The years 375–500 CE constituted the (pre-Slavic) Migration Period (D and E). Beginning in the early 4th century BCE, the Celtic peoples established a number of settlement centers. Most of these were in what is now southern Poland, which was at the outer edge of their expansion.