Frederick Charles Unknown Duke Schleswig Holstein Sonderburg Plön was appointed Duke Schleswig Holstein Sonderburg Plön.
[his daughter] was born to Frederick Charles Unknown Duke Schleswig Holstein Sonderburg Plön.
Caroline Amalie Oldenburg Queen Norway 1796-1881 x 1
Sophia Glücksburg Queen Consort Spain 1938- x 1
Constantine II King Hellenes 1940- x 1
Carl XVI King Sweden 1946- x 1