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 poses some problems of interpretation of the information regarding the attack of Margrave Gero on the Slavic tribes, as a result of which he purportedly "subordinated to the authority of the Emperor Lusatia and the Selpuli" (meaning the Słupian tribes) "and also Mieszko with his subjects". According to the majority of modern historians, Thietmar made an error summarizing the chronicle of Widukind, placing the Gero raid there instead of the fighting that Mieszko conducted at that time against Wichmann the Younger. Other sources make no mention of such conquest and of putting the Polans state on the same footing with