duchy · Poland, Lithuania and Russia

Duchy of Masovia

1138 CE – 1526 CE · capital Plock

The long-lived duchy of central Poland whose duke invited the Teutonic Knights and whose town of Warsaw became Poland's capital.

Origins

Masovia, on the middle Vistula with its centre at Plock, was given to Boleslaw IV the Curly under the testament of Boleslaw III in 1138. From 1199 it was held by Konrad I and his descendants, a branch of the Piasts that ruled it for over three centuries.

Rule and society

Exposed to raids by the pagan Prussians and Lithuanians, Konrad I invited the Teutonic Order in 1226 and gave it the land of Chelmno, a decision with lasting consequences. Masovia was a poor, heavily forested land with a large petty nobility. Its dukes often divided it into smaller duchies such as Plock and Rawa, and from 1351 they were vassals of the Polish king.

Decline and legacy

Janusz I made Warsaw his main seat in the early 15th century. When the last dukes, Stanislaw and Janusz III, died young in 1524 and 1526, Masovia was incorporated into the Kingdom of Poland (1385-1569), and Warsaw became the royal capital in 1596.

Lineage

Kingdom of Poland (1025-1385) 1025 CE – 1385 CEDuchy of MasoviaKingdom of Poland (1385-1569) 1385 CE – 1569 CE

Connections (4)

More states of Poland, Lithuania and Russia →

Cite this page
APA
The Epoch Institute. (2026). Duchy of Masovia. In The Epoch Institute States Register. https://the-epoch-institute.org/state/duchy-of-masovia
MLA
“Duchy of Masovia.” The Epoch Institute States Register, The Epoch Institute, 2026, https://the-epoch-institute.org/state/duchy-of-masovia. Accessed .
Chicago
The Epoch Institute. “Duchy of Masovia.” The Epoch Institute States Register. 2026. https://the-epoch-institute.org/state/duchy-of-masovia.
Harvard
The Epoch Institute (2026) ‘Duchy of Masovia’, The Epoch Institute States Register. Available at: https://the-epoch-institute.org/state/duchy-of-masovia (Accessed: ).

Last reviewed October 2026Random state ↻