Hans Albrecht, Hereditary Prince of Schleswig-Holstein
Hans Albrecht, Hereditary Prince of Schleswig-Holstein-Sonderburg-Glücksburg, since 1931 of Schleswig-Holstein was the Hereditary Prince of Schleswig-Holstein and the heir apparent to the Head of the House of Oldenburg. Hans Albrecht was the eldest son of Wilhelm Friedrich, Duke of Schleswig-Holstein and his wife Princess Marie Melita of Hohenlohe-Langenburg. The Hereditary Prince fought in the Second World War between 1939 and 1944 when he died from wounds received in action near Zedlinsk, Poland.- 12 May 1917 – 21 January 1934: His Highness Prince Hans Albrecht of Schleswig-Holstein-Sonderburg-Glücksburg
- 21 January 1934 – 10 August 1944: His Highness The Hereditary Prince of Schleswig-Holstein