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 I of Poland As a result, in 965 Mieszko I married his daughter Dobrawa (also named "Dobrava", "Doubravka" or "Dąbrówka"). This political Polish-Bohemian alliance is likely to have been initiated by the Polish ruler. It is probable that the marriage was officially arranged in February 965. The next step was the baptism of Mieszko. There are different hypotheses concerning this event. Most often it is assumed that it was a political decision, intended to bring Mieszko's state closer to the Czechs and to facilitate his activities in the Polabian Slavs area. At the same time, the baptism decreased the likelihood of future attacks