Czech involvement in King Henry V of Germany’s expedition against Poland in September 1109 from the perspective of Polish historiography

Abstract

In August and September 1109, a war was fought between Henry V, King of Germany, and Prince Bolesław Krzywousty (Boleslaus Wrymouth) of Poland. Henry’s expedition against Poland was a response to the Polish ruler’s actions of the previous year, when his attack on Bohemia sparked the fiasco of the German expedition to Hungary. It was then that King Henry V had vowed to exact his revenge on Bolesław Krzywousty.1 Henry was encouraged to retaliate by the Czech duke Svatopluk,2 not only as a means of gaining revenge for earlier events, but also because Svatopluk’s rival for the throne, Bořivoj, ousted in 1107, had found sanctuary in Poland. Before the war, the German king had sent an envoy demanding that Bolesław Krzywousty reinstate his older brother Zbigniew, who had been removed from power and exiled from Poland. He also demanded that Bolesław pay a tribute of 300 silver grzywnas (marks) or supply 300 knights for an expedition (to Italy, where Henry V intended to assume the crown of the Holy Roman Empire).