In 1146, High Duke Władysław II was driven into exile to Germany by his brothers, who opposed his attempts to strengthen control of High Duke over the remaining dukes. Silesia then became a possession of the new High Duke, Bolesław IV the Curly. Meanwhile, Władysław unsuccessfully tried to persuade Holy Roman Emperors Conrad III and his successor Frederick Barbarossa to aid him in retaking his duchy. In 1163, his three sons (Konrad, Mieszko and Bolesław) took possession of Silesia with Imperial backing and probably ruled it together until 1172, before dividing the territory. Bolesław received the area of Wrocław, Opole and Legnica, Konrad Żagań, Głogów and Krosno and Mieszko the smallest part with Ratibor and Cieszyn. As Konrad prepared himself in Fulda for a clerical career, his brother Bolesław administered his possessions until Konrad's early death, when Bolesław incorporated Konrad's domain into his duchy. Mieszko at the same time expanded his own duchy with parts of the Duchy of Kraków around Bytom and Oświęcim, which were given to him by Casimir II in 1178, and Opole, which he received after Bolesław's death. In 1202 Bolesław's son, Henry I, and Mieszko moreover specified to rule out the right of succession among their branches, an arrangement which was largely responsible for the special position of what would become Upper Silesia. In the same year Poland abolished the seniorate and Silesia's duchies became independent under constitutional law.