Testament of Bolesław III Wrymouth

The last will and testament of the Piast duke Bolesław III Wrymouth of Poland,[1] established rules for governance of the Polish kingdom by his four surviving sons after his death.

The Senior was tasked with defense of borders, the right to have troops in provinces of other Dukes, carrying out foreign policy, supervision over the clergy (including the right to nominate bishops and archbishops), and minting of currency.

With the help of Emperor Frederick I Barbarossa his sons managed to retain the Silesian Province in 1163, losing the Seniorate, which had passed to their uncle Bolesław IV.

This led to a period of nearly 200 years of Poland's feudal fragmentation; the estrangement of the Silesian Piasts deepening after the death of Duke Henry II the Pious at the disastrous Battle of Legnica in 1241.

Once Duke Władysław I the Elbow-high, a descendant of Casimir II the Just, was crowned King of Poland in 1320, he would reign on a smaller dominium, with Pomerelia lost to the State of the Teutonic Order and Silesia mostly vassalized by the Kingdom of Bohemia.

Fragmentation of Polish state in 1138 (in accordance with Testament of Bolesław III Wrymouth )
The Seniorate Province (Eastern Greater Poland , Western Kuyavia , Wieluń Land , Lesser Poland ) under Władysław II the Exile
Silesian Province of Władysław II the Exile
Masovian Province of Bolesław IV the Curly composed of Masovia and Eastern Kuyavia
Greater Poland Province of Mieszko III the Old composed of Western Great Poland
Sandomierz Province of Henry of Sandomierz , split off from the Seniorate Province
Łęczyca Province ( Łęczyca Land and Sieradz Land ) as Salomea of Berg 's dower
Pomerania , fiefdom of Poland under the control of the princely superior of Poland (princeps)
Poland subdivided into five provinces among the sons of Bolesław III