Duchy of Münsterberg
In 1269, Nicholas, bastard son of King Ottokar II who was legitimized by pope Alexander IV in 1260, became Duke of Opava. In 1337, his son Nicholas II inherited the Duchy of Ratibor. His four sons divided the Duchy of Opava (the Duchy of Ratibor was inherited only by the eldest, John). Thus started the partition of a once-unified land between the descendants of Nicholas II. In 1443, William, Duke of Opava gained the Duchy of Münsterberg, which was held by Přemyslids until 1456. This line of Opavian Přemyslids ended in 1521, with the death of Valentine, Duke of Ratibor.