Partitioned-off duke

Content sourced from Wikipedia, licensed under CC BY-SA 3.0.

In Schleswig and Holstein, a "partitioned-off duke" meant a duke whose land wasn’t fully recognized as ruling by the local nobles and towns. The story starts with the Treaty of Ribe in 1460, when it was agreed that Schleswig and Holstein would always be ruled by one sovereign in a personal union with Denmark. That promise was broken in 1544, when Christian III divided the lands between himself and his half-brothers John II the Elder and Adolf.

Later, when Christian’s son Frederick II tried to divide the land with his brother John II the Younger, the estates refused to recognize John II as ruler. John II was given the title of duke and the income from his own lands, but real power stayed with his brother and uncle. He started the Schleswig-Holstein-Sonderburg line of the House of Oldenburg. The partitioned-off duchy could not mint coins or maintain a standing army. After John II’s death, the land was split among his children, creating several branches of the Schleswig-Holstein-Sonderburg line.