Her Highness Princess Märtha Louise was born at Rikshospitalet University Hospital in Oslo on 22 September 1971. She is the oldest child of His Majesty King Harald and Her Majesty Queen Sonja. She has one brother, His Royal Highness Crown Prince Haakon.
The Princess was named after her father’s mother, Crown Princess Märtha, and her great-great grandmother, Queen Louise, the mother of King Haakon VII. A constitutional amendment adopted in 1990 established the right of eldest born child to succeed to the Throne regardless of gender; however, as the amendment entered into force long after the Princess and Crown Prince were born, it was decided that males would continue to take precedence over females for children born prior to 1990.
Princess Märtha Louise became engaged to the author Mr Ari Behn on 13 December 2001. The couple were married in Nidaros Cathedral in Trondheim on 24 May 2002. Bishop Finn Wagle presided over the ceremony. In 2016 the couple decided to part ways, and they were divorced in 2017.
The Princess and Mr Behn have three daughters, Miss Maud Angelica Behn, born at Rikshospitalet University Hospital in Oslo on 29 April 2003, Miss Leah Isadora Behn, born at the couple’s summer home, Bloksbjerg at Hankø, on 8 April 2005 and Miss Emma Tallulah Behn born at Lommedalen on 29. September 2008.
All three were christened in the Palace Chapel: Miss Maud Angelica 2 July 2003, Miss Leah Isadora 16 June 2005 and Miss Emma Tallulah 20 January 2009.
The Princess lives with her daughters in Lommedalen, in Bærum outside of Oslo.
Princess Märtha Louise undertakes official engagements as a representative of the Royal Family in areas concerning persons with disabilities.
She is also active as patron of eight organisations, and as Chair of Princess Märtha Louise's Fund. Allocations from the fund are awarded to projects that aim to benefit children with disabilities.
The Princess is a member of the board of Stiftelsen Vi (the Vi Foundation), established to work on behalf of disabled people for the equal right to a meaningful life.
Princess Märtha Louise has long been engaged in cultural work, and especially in disseminating traditional Norwegian fairy tales to a wider audience. Among other activities, she has starred in a storytelling series on Norwegian television. The Princess is the author of several books and audiobooks, and has participated in the production of television programmes for children.
The Princess established a sole proprietorship on 1 January 2002 under which she conducts her independent professional activities in the cultural sphere and as a Rosen therapist. As of that date she has been subject to Norwegian tax laws.
From 2007 to 2019 The Princess ran Astarte Education/Soulspring with Ms Elisabeth Nordeng. In 2018 she established the YouTube channel Hest360 with Mr Geir Kamsvåg.