Duchies of Silesia
Overview
 
The Duchies of Silesia resulted from divisions of the original Duchy of Silesia
Duchy of Silesia
The Duchy of Silesia with its capital at Wrocław was a medieval duchy located in the historic Silesian region of Poland. Soon after it was formed under the Piast dynasty in 1138, it fragmented into various Duchies of Silesia. In 1327 the remaining Duchy of Wrocław as well as most other duchies...

 after 1138.

In accordance with the last will and testament of Duke Bolesław III Wrymouth, the Kingdom of Poland was, upon his death in 1138, divided into five hereditary provinces distributed among his sons, including the Seniorate Province
Seniorate Province
Seniorate Province, also known as the Senioral Province , Duchy of Kraków , Duchy of Cracow, Principality of Cracow, Principality of Kraków, was the superior among the five provinces established in 1138 according to the Testament of Bolesław III Krzywousty...

 of Kraków
Kraków
Kraków also Krakow, or Cracow , is the second largest and one of the oldest cities in Poland. Situated on the Vistula River in the Lesser Poland region, the city dates back to the 7th century. Kraków has traditionally been one of the leading centres of Polish academic, cultural, and artistic life...

 reserved for the eldest, who was to be High Duke of all Poland. This act inadvertently started the process known as Fragmentation of Poland.

Bolesław's son, Władysław II the Exile received the Duchy of Silesia
Duchy of Silesia
The Duchy of Silesia with its capital at Wrocław was a medieval duchy located in the historic Silesian region of Poland. Soon after it was formed under the Piast dynasty in 1138, it fragmented into various Duchies of Silesia. In 1327 the remaining Duchy of Wrocław as well as most other duchies...

 and, as the eldest, was also granted the title of a High Duke among with the Seniorate Province of Kraków.
 
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