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 expanding and improving the so-called war monarchy system. According to existing sources, Mieszko I was a wise politician, a talented military leader, and a charismatic ruler. He successfully used diplomacy, concluding alliances, first with Bohemia, then Sweden, and the Holy Roman Empire. In foreign policy, he placed the interests of his country foremost, even entering into agreements with his former enemies. On his death, he left to his sons a country with greatly expanded territories, and a well-established position in Europe. Mieszko I also enigmatically appeared as "Dagome" in a papal document dating to about 1085, called "Dagome iudex", which