Sieradz

The Duchy of Sieradz was a Piast principality in central Poland, centered on Sieradz. In 1337 Przemysł of Inowrocław held it as a vassal of the Polish crown.

Przemysł died without heirs in 1339, and Casimir III incorporated the duchy directly into the Lands of the Polish Crown. The territory became the Sieradz Voivodeship and survived until the partitions of Poland in 1772 to 1795.