Marius Borg Høiby, the 29-year-old son of Norway's Crown Princess Mette-Marit, has been convicted on two charges of rape and handed a four-year prison sentence.
The panel of three judges in courtroom 250 at Oslo District Court acquitted him of two additional rape counts but determined he was guilty of numerous other charges he faced.
Høiby did not appear in person for the verdict due to unspecified medical reasons, instead participating in the hearing via video link.
Prosecutors had requested a sentence of seven years and seven months in prison for Høiby. His legal team argued for a reduced term of 18 months and have stated their intention to appeal.
Although Marius Borg Høiby is not a royal figure himself, the trial has cast a shadow over the wider royal family. His mother married Crown Prince Haakon when he was four, and he was raised within the family. The palace has indicated it will not comment on Monday's ruling.
Mette-Marit is seriously ill with a form of pulmonary fibrosis and has recently been placed on a waiting list for a lung transplant.
Her son's attorneys have repeatedly requested his release from custody so he could spend time with his mother due to her worsening condition.
Following the verdict, Høiby's defence lawyer Petar Sekulic again petitioned the court for his release. Although Oslo district court initially granted his release last week, that decision was reversed by the court of appeal.
One of the three judges in the trial, Judge Jon Sverdrup Efjestad, opened the session early on Monday with an overview of their findings, before presenting a 128-page ruling detailing the verdict.
Høiby had denied all four rape allegations, but the judges found him guilty of raping two women, including one incident at the Crown Prince's estate at Skaugum in 2018 and another involving a woman in Oslo in 2024.
He was also convicted of mistreating an ex-girlfriend, Norwegian influencer Nora Haukland, and of inflicting serious bodily harm on another partner, in whose apartment he was arrested in the upscale Frogner district of Oslo in August 2024.
However, he was cleared of two further rape charges, involving a woman he encountered at a hotel in Oslo in November 2024 and another he met while on vacation in the Lofoten islands in 2023.
Sekulic stated that it was "in the nature of the case that there could be an appeal".
His defence colleague Ellen Holager Andenæs told reporters they were pleased with the acquittals but were more critical of other elements of the ruling.
Both lawyers then went to discuss the verdict with Høiby at Ila prison and detention centre outside Oslo.
The case against Høiby involved six women, but only one of the women was present in court to hear the verdict, and she was observed crying as Høiby was found guilty of raping her.
Prosecutors argued that she had been either incapacitated or asleep when she was raped after a party in Oslo in March 2024, following consensual sexual activity.
The case relied on videos that Høiby had recorded at the time, and while giving evidence in February, the woman told the court that she was asleep and would never have consented to it.
The court agreed that the victim had been unable to resist what occurred.
All four rape charges involved women who had been either asleep or incapacitated at the time.
The judges also found it proven that the woman in the 2018 rape case had been asleep at the time and unable to resist Høiby. She only discovered that Høiby had recorded what happened last year.
Høiby was also found guilty of several offences including abuse and reckless behaviour towards the sixth woman in the case, who became known as the Frogner woman due to the area of Oslo where she resided.
The court ruled that he should pay a total of 640,000 kroner (£50,000; €57,000) in compensation to four of the women, including Nora Haukland, the only woman judges permitted to be named in the case.
Høiby's defence lawyers must now decide whether to appeal against the four-year prison term, which is higher than the 18 months the defence had proposed, due to the less serious charges that Høiby had admitted, including transporting 3.5kg of marijuana and traffic violations.
The palace said in an email to the BBC that "the matter has been considered by the courts, and we have no comment on the outcome." It has already made clear there will be no further statement on Mette-Marit's declining health until she has undergone a lung transplant.
"There is no doubt that this case has affected people's perception of the royal family," said Caroline Vagle, royal correspondent for Se og Hør magazine.
That was further compounded by revelations on the eve of the trial that the crown princess had had a three-year friendship with late sex offender Jeffrey Epstein.
But Vagle believes the mood now is completely different: "Her health is the main concern now - and it overshadows everything else."
Peggy Simcic Brønn, who is a specialist in reputation and public relations and professor emerita at BI Norwegian Business School, believes the royal family is in the midst of an institutional crisis.
"[The Høiby case] is a tragedy and a crisis for any family," she said.
"The way they handle it is let the person be convicted, let him serve his sentence, but try to make amends as a family for what that person has done to their reputation and the impact on the royal house itself."