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 from the second part of the name *Dago-mierz, since the merger in pronunciation of "sz" with the devoiced "rz" which would appear in this position is quite recent. However, some historians believe that the word "Dagome" is a melding of two names: the Roman Catholic "Dago," for "Dagobert" (Mieszko's hypothetical baptismal name), and the Slavic "Me," for "Mieszko." The Latin word "iudex" ("judge") would be used in the meaning of "prince." Another interpretation is that "Dagome iudex" is a corruption of "Ego Mesco dux" ("I, Prince Mieszko"). Mieszko I took over the tribal rule after his father's death ca. 950–960,