Duchy of Pless

The Duchy of Pless (or the Duchy of Pszczyna,German: Herzogtum Pleß, Polish: Księstwo Pszczyńskie) was a Duchy of Silesia, with its capital at Pless (present-day Pszczyna, Poland).

After the fragmentation of the Polish kingdom upon the 1138 Testament of Bolesław III Krzywousty the lands around the castellany of Pszczyna belonged to the Seniorate Province of Lesser Poland (Małopolska), until in 1177 Duke Casimir II the Just granted them to the Silesian duke Mieszko I Tanglefoot. Mieszko attached Pszczyna to his Duchy of Racibórz. The Racibórz branch of the Silesian Piasts became extinct with the death of Duke Leszek in 1336.

Before his death, Leszek together with several other Dukes of Silesia had accepted vassalization by King John of Bohemia in 1327, putting his duchy in the Bohemian Crown, acknowledged by King Casimir III the Great of Poland in the 1335 Treaty of Trentschin. In 1336, King John gave the Duchy of Racibórz with Pszczyna to the Přemyslid duke Nicholas II of Opava, who had married late Duke Leszek's sister Anna of Racibórz and ruled both duchies in personal union. In 1407 Nicholas's grandson John II, Duke of Opava and Racibórz, gave the territories of Pszczyna, Bieruń, Mysłowice, and Mikołów as a dowry to his wife Helena, a niece of the Polish king Jogaila. After the acquisition of several villages south of Żory in 1412, Helena, upon the death of her husband in 1424 ruled as a Duchess of Pless, succeeded in 1452 by her daughter-in-law, Barbara Rockenberg, wife of Helena's son, Nicholas V, Duke of Ratibor-Jägerndorf, and the duchy was downgraded to a state country within the Lands of the Bohemian Crown.

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