The Norwegian king’s eldest child, Princess Martha Louise, will marry her Hollywood partner, the self-professed shaman Durek Verrett, next summer.
King Harald V said in a statement that his family was “delighted to welcome” Mr Verrett, who is from California and claims to be a sixth-generation shaman.
The Norwegian princess can trace her ancestry back to Britain’s Queen Victoria.
The couple, who toured the country in 2019 as “The Princess and The Shaman”, have created waves in Norway with their alternative beliefs.
For the past several years, Martha Louise, 51, has said she can talk with angels, while Mr Verrett, 48, claims that he communicates with a broad range of spirits, wields ancient medicine and has a medallion which helps ward off heavy energies, spells and darkness.
The wedding will take place on August 24 in Geiranger, prized for its typical Norwegian scenery among mountains and fjords.
Geiranger is 265 kilometres (165 miles) north of Bergen, Norway’s second-largest city.
The VG newspaper, one of Norway’s biggest, said that the wedding would be privately paid for.
“We are incredibly happy to be able to celebrate our love in Geiranger’s beautiful surroundings. It means a lot to us to gather our loved ones in a place that is so rich in history and spectacular nature. Geiranger is the perfect place to embrace our love,” the couple said in a statement.
The state broadcaster NRK said that Mr Verrett will move to Norway.
And while he will join the royal family, he will not have a title.
Although Princess Martha Louise is the first child of King Harald V, her brother, Crown Prince Haakon, who is two years younger than her, will succeed his father as king.
The Norwegian Constitution was altered in 1990 to allow the first born, regardless of gender, to take precedence in the line of succession.
However, it was not done retroactively, meaning that Haakon remains first in line to the throne.
Haakon’s oldest child, Princess Ingrid Alexandra, will one day ascend the Norwegian throne.