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 Tanglefoot p. 876). This is the oldest preserved record of the Mieszko's nickname in the form of "Plątonogi". From 1146, after the deposition of his father, Mieszko and his family mainly lived in the town of Altenburg in Saxony, which was granted as a temporary possession to Władysław II by his brother-in-law, King Conrad III of Germany. During his time in exile, Mieszko studied in Michaelsberg and Bamberg. However, the supposed temporary exile was, for the deposed High Duke, for good; he died in Altenburg in 1159. His sons continued the fight to recover their inheritance, and finally three years later,