Upon the death of Duke Konrad III the Old in 1412, it was split off for his first-born son Conrad IV the Elder, who at first also ruled over the other Oels territories as a regent for his minor brothers until they formally divided their heritage in 1416.

After the Oels branch of the Piast dynasty died out in 1492, the duchy was seized as a reverted fief by King Vladislaus II of Bohemia.

In 1495, he gave the duchies of Bernstadt and Oels to Duke Henry the Elder of Münsterberg, a son of the late Bohemian king George of Poděbrady (d. 1471).

Due to lack of money, his heir Duke Charles of Münsterberg and Oels leased Bernstadt in 1511 for four years to the City Council of Breslau (Wrocław), afterwards he chose it as his residence.

Henry III's younger brother Duke Charles II of Münsterberg-Oels, who was Governor of Silesia at the time, bought it back in 1604.

Silvius, a devoted Lutheran, made great efforts to redevelop his estates, that had been devastated during the Thirty Years' War.