Mieszko II Lambert by the chronicles of Gottfried of Viterbo, refers to Bezprym. However, the historians now think that he was killed in a plot hatched by the aristocracy. He was buried in the Cathedral of St. Peter and St. Paul. After Mieszko II's death, Poland's peasants revolted in a "pagan reaction." The exact reasons and date are unknown. Mieszko II's only son and heir, Casimir I, was either expelled by this insurrection, or the insurrection was caused by the aristocracy's expulsion of him. Some modern historians argue that the insurrection was caused more by economic than by religious issues, such as new
Mieszko I of Poland As a result, in 965 Mieszko I married his daughter Dobrawa (also named "Dobrava", "Doubravka" or "Dąbrówka"). This political Polish-Bohemian alliance is likely to have been initiated by the Polish ruler. It is probable that the marriage was officially arranged in February 965. The next step was the baptism of Mieszko. There are different hypotheses concerning this event. Most often it is assumed that it was a political decision, intended to bring Mieszko's state closer to the Czechs and to facilitate his activities in the Polabian Slavs area. At the same time, the baptism decreased the likelihood of future attacks