Silesian dukes

The Duke of Silesia was the sons and descendants of the Polish Duke Bolesław III Wrymouth. In accordance with the last will and testament of Bolesław, upon his death his lands were divided into four or five hereditary provinces distributed among his sons, and a royal province of Kraków reserved for the eldest, who was to be High Duke of all Poland. This was known as the fragmentation of Poland. Subsequent developments lead to further splintering of the duchies.

At the beginning of the 14th century, fourteen independent Duchies existed in Silesia: Brzeg, Wrocław, Świdnica, Jawor, Ziębice, Głogów, Ścinawa, Żagan and Oleśnica in Lower Silesia; Koźle, Cieszyn, Bytom, Niemodlin, Opole, Strzelce, Racibórz and Opava in Upper Silesia and the eclessiatical duchy of Nysa. Between 1327 and 1329 most dukes accepted the overlordship of Bohemian king John of Bohemia, who acquired the right of succession for all of these duchies. In the coming centuries all branches of the Silesian Piasts died out, and with the death of George William, Duke of Liegnitz the dynasty ceased to exist.

The Duchy of Silesia, one of the hereditary provinces of Poland, Silesia, was granted to Bolesław III's eldest son, Władysław II the Exile, and was subsequently divided among his sons Bolesław I the Tall (Wrocław/Lower Silesia), Mieszko I Tanglefoot (Racibórz/Upper Silesia) and Konrad Spindleshanks (Głogów). After Konrad's death Głogów was again united with the Duchy of Wrocław/Lower Silesia.

In 1173 Bolesław returned and he agreed to let Mieszko and Bolesław rule in their own Duchies, separated from the Duchy of Silesia. This led to the creation of the Duchy of Racibórz for Mieszko I and the Duchy of Opole for Jarosław, beginning the fragmentation of the Duchy of Silesia. The territories controlled by Mieszko I and Jarosław roughly corresponded to what is known as Upper Silesia, while the territories remaining with Bolesław I roughly corresponded to Lower Silesia.

...
Wikipedia