Mieszko the Younger time in 1166 or 1167 in a document signed between Mieszko III and Casimir II the Just at the congress in Jędrzejów as one of the sons of the Duke of Greater Poland. Between 1177 and 1179, as a result of the revolt against his father, Mieszko, with his parents and siblings, were exiled from Poland. They probably returned to the country in 1181, when Mieszko III regained the rule over Greater Poland. In 1184 and thanks to the wise diplomatic affairs of his father, Mieszko the Younger was appointed by the sickly Duke Leszek Governor of the Masovian-Kuyavian principality,
Mieszko II Lambert talented ruler. Since Mieszko II was politically active before his father's death, Bolesław I appointed him as his successor. He participated mainly in German politics, both as a representative of his father and the commander of the Polish troops. In 1013 Mieszko II went to Magdeburg, where he paid homage to the Emperor Henry II. A few months later Bolesław I paid homage in person. The real purpose of Mieszko's visit is unclear, especially since soon after his father paid homage to the Holy Roman Empire. Presumably, the young prince paid homage for Milsko or Moravia and Lusatia. The relevant