Almanach de Saxe Gotha - King Frederick IX of Denmark / Frederick IX (Christian Frederik Franz Michael Carl Valdemar Georg) (11 March 1899 – 14 January 1972) was King of Denmark from 1947 to 1972. He was the son of King Christian X of Denmark and Queen Alexandrine, born Duchess of Mecklenburg, and the fourth Danish monarch of the House of Glücksburg.