# Testament of Bolesław III (1138)

URL: https://poland-history.com/timeline/1138-testament-of-boleslaw-iii
Location: Poland
Categories: main-event

Bolesław's testament divided Poland among his sons under the seniorate principle, giving the eldest Kraków and supreme authority. The arrangement soon failed, beginning almost two centuries of fragmentation. Within the broader Fragmentation period: After 1138 Poland split into duchies ruled by rival Piast princes. Mongol invasions, German settlement, the growth of towns and the arrival of the Teutonic Knights reshaped the land before it was reunited. At this point in the timeline (28 October 1138), the governing authority was Władysław II the Exile (High Duke of Poland). Eldest son of Bolesław III and first senior duke; his attempt to reunite the realm ended with expulsion by his half-brothers. Testament of Bolesław III mattered because it altered the structure of power and the direction of Polish statehood. The event is placed here so readers can follow it alongside changes in government, warfare, society, religion and culture across Polish history.

## Why it matters
Testament of Bolesław III mattered because it altered the structure of power and the direction of Polish statehood.

Ruler at the time: [Władysław II the Exile](https://poland-history.com/rulers/wladyslaw-ii-the-exile)

## Sources
- [Wikipedia — Testament of Bolesław III Wrymouth](https://en.wikipedia.org/wiki/Testament_of_Boles%C5%82aw_III_Wrymouth)
- [Encyclopaedia Britannica topic lookup — Testament of Bolesław III](https://www.britannica.com/search?query=Testament+of+Boles%C5%82aw+III)
- [Wikipedia — History of Poland during the Piast dynasty (period overview)](https://en.wikipedia.org/wiki/History_of_Poland_during_the_Piast_dynasty#Fragmentation_of_the_realm_(1138%E2%80%931320))