duchy · Poland, Lithuania and Russia

Duchy of Sieradz

1263 CE – 1339 CE (approx.) · capital Sieradz

A Piast duchy in central Poland, a stepping stone for Leszek the Black and Wladyslaw the Elbow-high on their way to Krakow.

Origins

Sieradz, on the Warta, was part of the lands of Casimir I of Kuyavia. In the early 1260s his eldest son Leszek the Black received it as his own duchy, which he kept after his father's death in 1267.

Rule and society

It was a farming land on the borders of Greater Poland and Silesia. Leszek the Black used it as a base to become duke of Krakow in 1279, and later his half-brother Wladyslaw I the Elbow-high held Sieradz as he fought for the reunification of Poland. Its towns were developed under German law in the 13th century.

Decline and legacy

After 1320 Sieradz remained a duchy within the reunited kingdom, held by Przemysl, a nephew of the king. When he died in 1339 it was incorporated into the Kingdom of Poland (1025-1385) and later became the Sieradz Voivodeship.

Lineage

Duchy of Leczyca 1229 CE – 1352 CEDuchy of SieradzKingdom of Poland (1025-1385) 1025 CE – 1385 CE

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

Last reviewed October 2026Random state ↻