Schleswig-Holstein-Sonderburg-Plön-Rethwisch
The ducal line of Schleswig-Holstein-Sonderburg-Plön-Rethwisch descended from the line of Schleswig-Holstein-Sonderburg-Plön. It was founded by Joachim Ernest II who as the third son of the Duke of Plön, Joachim Ernest, received the estate of Rethwisch in Storman as his inheritance. He was a general to the Spanish royal house in the Netherlands and became a Roman Catholic in 1673.
The line laid claim to the domain of Plön; this was rejected however by the King of Denmark. John Ernest Ferdinand appealed to the Supreme Court and was vindicated. He died without leaving living descendants.
