was he a part of any war?
German civil war
Mieszko I
The role played by Mieszko I in the subsequent struggles is unclear because the contemporary sources are scarce and not in agreement. Probably in 985 the Polish ruler ended his support for the Bavarian duke and moved to the side of the Emperor. It is believed that Mieszko's motivation was the threat posed to his interests by the Polabian Slavs uprising. 
when did the third silesian war take place? 1756 to 1763 between whom did it happen? Between Prussia and Austria where did it begin? The war was fought mainly in Silesia, Bohemia and Upper Saxony where is the first one located? It is a historical region of Central Europe mostly in Poland, with small parts in the Czech Republic and Germany. where did the first country get it's name from? The origin of the name "Poland" derives from the West Slavic tribe of Polans ("Polanie") was it under the reign of any king? Under the Piast dynasty, Poland's first historically documented ruler, Mieszko I
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Mieszko I [SEP] Participation in German civil war
Like in 973, Mieszko and the Czech duke Boleslav II took the side of the Bavarian duke. This fact is confirmed in the chronicle of Thietmar: In 984 the Czechs took over Meissen, but in the same year Henry II gave up his pretension to the German throne. The role played by Mieszko I in the subsequent struggles is unclear because the contemporary sources are scarce and not in agreement. Probably in 985 the Polish ruler ended his support for the Bavarian duke and moved to the side of the Emperor. It is believed that Mieszko's motivation was the threat posed to his interests by the Polabian Slavs uprising.