Mieszko, initially ruled the Duchy of Racibórz with Cieszyn and Oświęcim, jointly with his minor brother Przemysław. After another partition in 1290, Mieszko took his residence in Cieszyn and became the first Duke of Teschen. Piast rule Like most of his Silesian Piast relatives, Mieszko approached the mighty kings of Bohemia; during the Polish internal struggles after the death of High Duke Leszek II, in 1291, he and his younger brother Duke Bolko I of Opole signed a support agreement with King Wenceslaus II. Mieszko also had the Teschen lands on the Vistula and Biała rivers and the Beskid foothills settled by German immigrants. He colonised the remote parts of his duchy and vested Cieszyn, Oświęcim, Zator, Skoczów and Karviná with town privileges. His adhered to the alliance with Bohemia even after in 1310 the House of Luxembourg assumed the throne in Prague. After Mieszko's death in 1315, his son Władysław took the lands east of the Biała river where he established the separate Duchy of Oświęcim, which eventually became a fief of the Polish Crown. His brother Casimir I retained the western part and in 1327 swore homage to King John of Bohemia. After that Teschen became an autonomous fiefdom of the Bohemian kings and part of the Crown of Bohemia. Local Piast rulers often possessed other lands outside the duchy itself, as the Duchy of Siewierz, half of Głogów and some parts of Bytom. After the death of Duke Bolesław I in 1431, the rule over the duchy was shared by his wife Euphemia and their four sons. In 1442 the duchy was divided between the brothers who all bore the ducal title; nevertheless, the real control over the duchy passed to Boleslaus II and Przemyslaus II, who after the death of Boleslaus II in 1452 ruled alone. From the late 15th century onwards, the Beskid valleys in the south were settled by Vlach peasants from neighbouring Moravian Wallachia. While the Lands of the Bohemian Crown passed to the Habsburg dynasty in 1526, the Duchy of Teschen during the reign of Duke Wenceslaus III Adam, from 1528 onwards, shifted to Protestantism. Influenced by the Moravian governor John of Pernstein, his tutor and father-in-law, he turned to the Lutheran faith in 1540 and his subjects had to follow according to the cuius regio, eius religio rule. In 1560, still during his lifetime, he ceded the Duchy of Bielsko with