Wikipedia
Schleswig-Holstein-Sonderburg-Franzhagen
The Schleswig-Holstein-Sonderburg-Franzhagen line was a short-lived name of the main line of the ducal house of Schleswig-Holstein-Sonderburg, after its bankruptcy in 1667. The name is derived from the Franzhagen Castle in Schulendorf in the duchy of Saxe-Lauenburg. The castle was inherited by Eleonore Charlotte of Saxe-Lauenburg-Franzhagen, who brought it into her marriage with former Duke Christian Adolph I. After their bankruptcy, the Sonderburg line was reduced to its possession of Franzhagen. The Franzhagen castle was demolished in 1716.