The Duchy of Opole and Racibórz (, ) was one of the numerous Duchies of Silesia ruled by the Silesian branch of the royal Polish Piast dynasty. It was formed in 1202 from the union of the Upper Silesian duchies of Opole and the Racibórz, in a rare exception to the continuing feudal fragmentation of the original Duchy of Silesia. In 1281 it was split again. In 1521 it was recreated by the last Silesian Piast, Duke Jan II the Good. After his heirless death the duchy fell to the Kingdom of Bohemia. It was briefly part of the Polish–Lithuanian Commonwealth in the 17th century; eventually like most of the then mainly German-speaking province of Silesia it was annexed by Prussia after the First Silesian War in 1742. First duchy The Duchy of Racibórz under Duke Mieszko Tanglefoot had been established in 1173 upon the partition of Silesia among the sons of Duke Władysław II the Exile. The bulk of the Silesian lands around Wrocław had passed to Mieszko's elder brother Duke Bolesław I the Tall, leaving the younger dissatisfied. After Bolesław had died in 1201, Mieszko occupied the Duchy of Opole, that had been created for his deceased nephew Jarosław, forming the united duchy of Opole and Racibórz. Bolesław's heir, Duke Henry I the Bearded, had to renounce his claims, whereby the centuries-long division of Upper and Lower Silesia was fixed. The dukes took their residence at the castellany of Opole. Mieszko's son Casimir I of Opole, Duke from 1211, invited German settlers immigrating to his duchy in the course of the Ostsiedlung, and granted German town law to settlements like Leśnica, Ujazd, Gościęcin, Biała and Olesno. As Casimir's successor Duke Mieszko II the Fat was still a minor upon his father's death in 1230, the regency over his duchy was assumed by his uncle Henry I the Bearded, who thereby once again ruled over all Silesia. In 1233 Henry, then High Duke of Poland, granted Mieszko's younger brother Władysław the Greater Polish lands of Kalisz, which he had seized from Duke Władysław Odonic. However, Henry's plans to push off his nephews ultimately failed: when Mieszko II came of age he took over the rule of Opole-Racibórz, defying the claims raised by Henry's heir, High Duke Henry II the Pious. The Greater Polish territories were finally lost to Duke Przemysł I until 1249. In 1246 Mieszko II was succeeded