Märtha Louise, the only daughter of Norway's King Harald V and Queen Sonja, said in a press release that the distance between the two had grown to a point that there was no longer a chance of repairing their relationship.
"Life does not always go smoothly. Both Ari and I have experienced this. But that is markedly the case now, when, life has taken some twists and turns that we had never envisaged," wrote in a press release issued by the Royal Court. "Today, we are going our separate ways. We are ending the marriage but we are remaining together in parenthood."
Märtha Louise has long embarrassed Norway's court with her claims to communicate with angels and her business partnership with the controversial healer and spiritualist Elisabeth Nordeng.
When she married novelist Ari Behn in Tronheim's Nidaros Cathedral on 24 May 2002 he was seen as a controversial choice, Norway's state broadcaster NRK recalled on Friday. At the time, he had recently made a television programme showing prostitutes taking cocaine in Los Angeles, after which he refused to answer questions over his own drug use.
But Märtha Louise was adamant that Behn was the man for her. "Here is the man that makes me shine. Here is the man who brings out the best in me. Here is the man who I want to share the rest of my life with," she told the BBC in 2001.
The couple have three daughters, Maud Angelica Behn, born on 29 April 2003, Leah Isadora Behn, born on 8 April 2008, and Emma Tallulah Behn, who was born on 29 September 2008. They have decided on joint custody of their children.
The King and Queen said they were saddened by the news.
"Many people are affected when a marriage dissolves. It's painful and sad for the people around them as well," they said in a joint statement in the press release. "We like Ari very much and we are grateful for everything we have experienced together as a family. We want a good relationship with Ari in the future."
In her statement, Märtha Louise said that she and Behn had struggled for "a long time" to rescue their relationship.
"It's unspeakably sad for the two of us to realise that the road ahead will not be together like it was," she said. "It is terrible to realise that there is nothing more we can do."