Princess Märtha Louise of Norway (born 22 September 1971) is the only daughter and elder child of King Harald V and Queen Sonja. She is fourth in the line of succession to the Norwegian throne, after her brother Haakon, and his two children.

Princess Märtha Louise was born on 22 September 1971 in Rikshospitalet, Oslo, to the then Crown Prince Harald and Crown Princess Sonja. At birth, she was not in line to the throne, because until 1990, only males could inherit the Norwegian throne (Salic law). She was christened a few months after her birth. Her godparents are King Olav V of Norway, Princess Margaretha of Sweden, Count Flemming of Rosenborg, Princess Ragnhild of Norway, Dagny Haraldsen, Haakon Haraldsen, Nils Jørgen Astrup and Ilmi Riddervold.

In 1973, Märtha Louise’s younger brother was born Haakon Magnus. In 1990 the Norwegian constitution was altered, granting full cognatic primogeniture to the Norwegian throne, meaning that the eldest child, regardless of gender, takes precedence in the line of succession. This change only affects those born in 1990 or later. Females born between 1971 and 1990 (i.e. only Märtha Louise), were given succession rights, but their brothers would be before them in the line of succession, meaning that Prince Haakon still took precedence over Märtha Louise in the line of succession.

After the births of her brother’s two children, Ingrid Alexandra and Sverre Magnus, Märtha Louise was relegated to fourth in line. The princess is also in the line of succession to the thrones of the sixteen Commonwealth realms, as a great-great-granddaughter of King Edward VII of the United Kingdom.

Princess Märtha Louise is a certified physiotherapist, following education in Oslo and internship in Maastricht, the Netherlands. She has not practised her profession, however, choosing instead, from her fascination in traditional Norwegian folk tales as well as a love of music, to establish her own commercial entertainment business based on giving public and televised performances reciting folk tales and singing with well-known Norwegian choirs. In December 2003, she took part in Oslo Gospel Choir’s Christmas concert with a solo performance, included on the companion CD album.

On 1 January 2002, after Princess Märtha Louise started her own business, in order to work with more freedom from her constitutional role as a princess, she began paying income tax, and the King, after consulting her, issued a royal edict which removed Princess Märtha Louise’s style of Royal Highness (she is entitled to the style Highness when abroad). However, she retains her place in the line of succession, and, though her activities were reduced, she still carries out some public duties on behalf of the King.

After several postponements due to family births and her father’s illness, during which the princess took on some representation duties, Princess Märtha Louise and her husband moved to New York City in October 2004. In 2004, her first book, a children’s story about the first royal family of Norway was released – Why Kings and Queens Don’t Wear Crowns. Accompanying the book is a CD version of the Princess reading her story aloud.

Princess Märtha Louise has studied physiotherapy, trained as a Rosen therapist and studied at an academy for holistic medicine. She claims she can communicate with animals and angels and started her own alternative therapy center named Astarte Education, after one of the oldest goddesses in the Middle East. The princess drew criticism in Norway after the announcement that she would start Astarte Education. The newspaper Bergens Tidende, called for her to give up her royal titles. Norwegian state director of Health Lars E. Hanssen, Norwegian alternative medicine advocate Dr. Bernt Rognlien, Norwegian University of Science and Technology (NTNU), religious historian Asbjørn Dyrendal and University of Oslo theology professor Inge Lønning all expressed misgivings about the princess’ plans.
On 11 August 2007, Märtha Louise defended the school on NRK, the Norwegian public service television network.
On 2 October 2007, Princess Märtha Louise became the first member of the Norwegian Royal Family to ever appear in a court of law as she wanted to halt sales of a book entitled Martha’s angels.
In 2007 the Princess was editor of the book “Prinsesse Märtha Louises eventyrlige verden, Eventyr fra jordens hjerte, Rodinia” containing 67 fairy tales from 50 countries.

Her Royal Highness Princess Märtha Louise’s Fund was founded on 15 September 1972 and awards funds to projects carried out by non-governmental organisations in order to provide assistance to disabled children under the age of 16 in Norway. Princess Märtha Louise is the fund’s chairperson. In 2005 the fund had assets of approximately NOK 13,285,000, and total annual allocations came to about NOK 500,000
On 18 January 2006 Princess Martha Louise (along with the rest of the Norwegian Royal Family) revised her patronage list, and will no longer be a royal patron of any cultural groups including the annual Bjørnson literary festival; her brother Crown Prince Haakon will take over that position. She will only retain six patronage roles, all of them health related. They include the country’s foundations for the blind, deaf and those with epilepsy. “With these changes, we want to eliminate possible doubt about role conflicts for the princess.” palace spokesman Astrid Versto told newspaper VG.

The Norwegian Sports Organisation for the Disabled
The Norwegian Association of the Deaf
Norway Muscular Dystrophy Association
The Norwegian Epilepsy Association
The Norwegian Rheumatism Association
The Norwegian Association of the Blind and Partially Sighted

On 24 May 2002 Princess Märtha Louise married in Trondheim author Ari Behn (born 1972 as Ari Mikael Bjørshol; he later took his grandmother’s name). Princess Märtha Louise and Ari Behn have three daughters. The family has lived in Islington, London and Lommedalen, Bærum. They currently live in Lommedalen, Norway, since May 2014.

The couple have three daughters:

Maud Angelica Behn, born on 29 April 2003 (age 13) her godparents are Haakon, Crown Prince of Norway (maternal uncle), King Harald V (maternal grandfather), Anja Sabrina Bjørshol (paternal aunt), Princess Alexandra of Sayn-Wittgenstein-Berleburg (maternal grandfather’s second cousin once removed), Marianne Ulrichsen, Kåre Conradi and Trond Giske
Leah Isadora Behn, born on 8 April 2005 (age 11) her godparents are Queen Sonja of Norway (maternal grandmother), Espen Bjørshol (paternal uncle), Princess Laurentien of the Netherlands, Gry Brusletto, Katharina Salbu, Didrik Vigsnæs and Jon Andreas Håtuna.
Emma Tallulah Behn, born on 29 September 2008 (age 7) her godparents are Marianne Solberg Behn (paternal grandmother), Mette-Marit, Crown Princess of Norway (maternal uncle’s wife), Princess Alexia of Greece and Denmark (maternal grandfather’s second cousin once removed), Christian Udnæss, Carl Christian Christensen, Anbjørg Sætre Håtun, and Sigvart Dagsland.
Liv Mildrid Gjernes designed the Norwegian government’s gift for the couple, two cupboards entitled “Ikons for the Hearts”. In each cupboard there were seven exclusive pieces of handicraft, from different regions of Norway, produced by other Norwegian artisans.
On 5 August 2016, the Royal Court announced that Princess Märtha Louise and Ari Behn are separating and starting divorce proceedings but will have joint custody of their three daughters. The divorce is the first in the modern history of the Norwegian Royal Family.