The Duchy was established as a Christian Duchy in the early 12th century and submitted to the Roman Catholic Archdiocese of Gniezno. It was a fief of the Kingdom of Poland in the mid-12th century. Its only ruler known by name was Iakša de Kopnik (1120-1176) of the Gryfici (Świebodzice) noble clan, a knight of the Order of the Holy Sepulchre.Fritze, Wolfgang H. (1982). Frühzeit zwischen Ostsee und Donau. Duncker & Humblot. p. 356. .Cetwiński, Marek (1980). Rycerstwo Śląskie do końca XIII w. Pochodzenie. Gospodarka. Polityka. Wrocławskie Towarzystwo Naukowe. p. 70. Iakša's prominent relative Eric of Pomerania (1381-1459, House of Griffins) continued the family tradition and also became a knight of the Order of the Holy Sepulchre.
