Mieszko III the Old attention of Emperor Frederick Barbarossa, who offered his help in his restoration on the Polish throne after a payment of 10,000 pieces of silver, a sum that Mieszko couldn't reunited. Finally in Pomerania, his other son-in-law Duke Bogislaw I accepted to help him. By the agency of his Pomeranian allies, Mieszko forged his links with their Polish followers, grouped around Zdzisław, Archbishop of Gniezno and in 1181 was able to conquer the eastern Greater Polish lands of Gniezno and Kalisz, which until then had been part of the Seniorate Province. Soon after, Mieszko also managed to recover western Greater Poland.
Mieszko I of Poland to the Warta River). In all probability Mieszko decided to pay tribute in order to avoid an invasion similar to the one that Lusatia had suffered. This homage would take place in 965, or in 966 at the latest. Very likely the tribute applied only to the Lubusz land, which was in the German sphere of influence. This understanding of the tribute issue explains why already in 967 Mieszko I was described in the Saxon chronicles as the Emperor's friend (or ally, supporter, Latin: "amicus imperatoris"). Probably in 964 Mieszko began negotiations with the Bohemian ruler Boleslav I the Cruel.