Bolesław IV the Curly
During his first years, Casimir and his sister Agnes (born in 1137) lived with their mother Salomea in her widow land of Łęczyca. There, the young prince remained far away from the struggles of his brothers Bolesław IV the Curly and Mieszko III the Old with their older half-brother High Duke Władysław II, who tried to reunite all of Poland under his rule (contrary to his late father's testament) and was finally expelled in 1146.