A Norwegian court on Monday found Marius Borg Hoiby, the eldest son of Norway’s crown princess and a stepson of the country’s heir, guilty of rape and domestic violence, in a case that has drawn intense attention across Europe.

Mr. Hoiby, 29, was also convicted on charges including filming people without their consent and violent threats. Mr. Hoiby, who is not a member of Norway’s royal house, was sentenced to four years in prison, a judge said.

Mr. Hoiby had denied some of the prosecution’s accusations, though he pleaded guilty to other charges, including assault, harassment and malicious damage to property. He also admitted to transporting more than seven pounds of cannabis and violating a restraining order.

The court in Oslo found Mr. Hoiby guilty on two counts of rape and acquitted him on two other counts of rape. Still, the court ordered him to pay punitive damages to all four women who had accused him of rape, for a total of nearly $61,000. He was also acquitted on two counts of violating a restraining order.

Lawyers for one of the women, who had accused Mr. Hoiby of raping her in a hotel in Oslo, said that they planned to review the ruling after he was acquitted on that charge.

“She is disappointed with the outcome, but the case may not yet be finally settled,” the law firm, Elden Attorneys, said in a statement.

Two other victims represented by the same law firm, including Mr. Hoiby’s former girlfriend Nora Haukland, said in a statement that they were relieved that the trial had finally come to a close.

The trial, which lasted about a month and a half, garnered breathless coverage in Norway and attracted rare international attention to the country’s court system. Prosecutors were eager to show that Mr. Hoiby, a stepson of the future king, Crown Prince Haakon, would be tried as an ordinary citizen. The royal family stayed away from the court proceedings in a show of noninterference and issued public statements expressing sympathy for the victims.

After the verdict, a spokesman for the royal family said, “The case has been handled by the court, and the Royal House has no comment on the outcome.”

While Mr. Hoiby is not a member of Norway’s royal house, his relation to the family has made him a public figure. He was 4 years old when his mother married into the royal family, and although he has no title or official duties, he was often pictured with its members at formal events.

Mr. Hoiby had been treated “neither better or harsher than anyone else would have been in the justice system,” said Ole-Jorgen Schulsrud-Hansen, a historian of Norway’s royal family. “It’s in the extreme cases that principles are put to the test. And now they have been.”

But the criminal trial, which began in February, came after years of tabloid scandals and accusations about Mr. Hoiby’s behavior, especially toward women.

It also unfolded during a time of crisis for the Norwegian royal family as his mother, Crown Princess Mette-Marit, came under pressure for her past ties to Jeffrey Epstein, the American sex offender. The princess, who was diagnosed with pulmonary fibrosis in 2018, was placed this month on a waiting list for a lung transplant.

Last week, an appeals court rejected Mr. Hoiby’s request for release to be with his mother as her illness worsened. Mr. Hoiby has remained in police custody since his arrest in February, days before his trial was to begin, in connection with allegations of assault in a separate case.

The current trial focused on accusations of rape between 2018 and 2024; accusations of violence and threats against a former partner between 2022 and 2023; and accusations of violence against a subsequent partner.

Parts of the trial took place behind closed doors, but testimony in open court focused on Mr. Hoiby’s volatile relationships and on allegations of his violent responses.

The women who testified against him described multiple instances of physical and verbal violence. Ms. Haukland, his former girlfriend, said that some of those incidents had taken place in a royal residence where Mr. Hoiby lived with her, according to reports by Norway’s national broadcaster. He told the court, the broadcaster reported, that he had struggled with anger since he was a child and had sought help.

Referring to the way the case was tried, Katrine Holter, an associate professor at the Norwegian Police University College, said, “Hoiby is not receiving special treatment.”

“But,” she added, “one can probably say that he is being treated like other celebrities, in the sense that celebrity cases tend to run longer in court than cases that don’t receive media attention.”