Frederick IX of Denmark was born 11 March 1899 Sorgenfri in Kongens Lyngby, Denmark to Christian X of Denmark (1870-1947) and Alexandrine von Mecklenburg-Schwerin (1879-1952) and died 14 January 1972 Copenhagen, Denmark of unspecified causes. He married Ingrid av Sverige (1910-2000) 24 May 1935 in Stockholm, Sweden. Johan Willem Friso van Nassau-Dietz (1687-1711)/s, Willem van Oranje (1533-1584)/s.
|Offspring of Frederick IX of Denmark and Ingrid av Sverige (1910-2000)|
|Margrethe II of Denmark (1940-)||16 April 1940 Copenhagen, Denmark||Henri de Laborde de Monpezat (1934-2018)|
|Benedikte of Denmark (1944-)|
|Anne-Marie of Denmark (1946-)||30 August 1946 Amalienborg Palace, Copenhagen, Denmark||Constantine II of Greece (1940-)|