Mieszko I of Poland death occurred from causes other than natural. According to Thietmar the Polish ruler died "in an old age, overcame with fever". Probably he was buried in the Poznań Cathedral. The remains of the first historical ruler of Poland have never been found and the place of his burial is not known with certainty. In 1836–1837 a cenotaph was built for Mieszko I and his successor Bolesław I the Brave in the Golden Chapel () at the Poznań Cathedral, where the damaged remains found in the 14th century tomb of Bolesław were placed. According to Thietmar Mieszko I divided his state
Mieszko I of Poland situation at that time. Another debatable point is Thietmar's claim that Mieszko "subordinated himself to the King". Most historians believe that it was only a matter of recognition of Otto's royal authority. Some suggest that a fealty relationship could in fact be involved. Whether or not the German-Polish invasion of Bohemia actually happened, the friendly relations between the Czechs and the Poles came to an end. Bohemia resumed its earlier alliance with the Lutici, which caused in 990 a war with Mieszko, who was supported by Empress Theophanu. Duke Boleslav II was probably the first one to attack. As a