The Royal wedding in Denmark Some of the royal guests pictured in the church at Fredensborg Castle , Copenhagen , 3 February 1968 . during the marriage ceremony for 23-year-old Princess Benedikte , daughter of King Frederick and Queen Ingrid of Denmark , and German Prince Richard of Sayn-Wittgenstein-Berleburg . Seen back row . bottom to top : King Gustav of Sweden ; Queen Elizabeth the Queen Mother of Britain ; King Olav of Norway . Front row. bottom to top : King Frederick ; Queen Ingrid ; Princess Margarethe of Denmark , Prince Henrik of France ; Queen Anne-Marie of Greece (almost hidden) ; King Constantine of Greece , and their daughter Princess Alexia