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 in the hands of Bohemia. Sandomierz under this scenario was the central hub of the area, with Czerwień, Przemyśl and Chełm assuming the function of defensive borderland strongholds. After the death of Emperor Otto I in 973 Mieszko, like his brother-in-law, Duke Boleslav II of Bohemia, joined the German opposition in support of the attempted imperial succession of Henry II, Duke of Bavaria. Mieszko may have been motivated by revenge because of the (presumably) negative verdict of the Quedlinburg summit, but, more importantly, he may have wanted more favorable terms for his cooperation with Germany. The participation of Mieszko in