Johan Martin Ferner (né Johan Martin Jacobsen; 22 July 1927 – 24 January 2015) was a Norwegian sailor and Olympic medalist. He won a silver medal in the 6 metre class with the boat Elisabeth X at the 1952 Summer Olympics in Helsinki, together with Finn Ferner (his brother), Erik Heiberg, Tor Arneberg and Carl Mortensen. He was married to Princess Astrid, the sister of King Harald V of Norway and Princess Ragnhild.
Princess Ragnhild, Mrs Lorentzen (Ragnhild Alexandra; 9 June 1930 – 16 September 2012), was the eldest child of King Olav V of Norway and Princess Märtha of Sweden. She was the older sister of King Harald V and Princess Astrid. She was the first Norwegian royal to have been born in Norway since the Middle Ages. In 1953 she married the industrialist Erling Lorentzen, a member of the Lorentzen family of shipping magnates. In the same year they moved to Brazil, where her husband was an industrialist and a main owner of Aracruz Celulose. She lived in Brazil until her death 59 years later.
Although she was the King's eldest child, she was never in the line of succession to the Norwegian throne, owing to Norway's law of agnatic succession. She was in the line of succession to the British throne, and occupied the 16th and 17th place in that succession line during her childhood and youth.