Marius Borg Høiby (born 13 January 1997) is a relative of the Norwegian royal family and the eldest child of Mette‑Marit, Crown Princess of Norway. He became the stepson of Crown Prince Haakon when his mother married the Crown Prince in 2001. Although he has appeared with the royal family on several occasions, he holds no royal titles, succession rights, or official public duties.
Since 2017, Høiby has been involved in a series of criminal matters relating to allegations of violence, drug use, and breaches of a restraining order. In August 2025, he was indicted on four counts of rape and dozens of additional offences, including domestic violence and abuse in intimate relationships. His trial began in Oslo District Court in early 2026. He pleaded not guilty to the rape charges but admitted some offences, including aggravated assault, reckless behaviour, and transporting marijuana. The case has been described in Norwegian media as one of the most extensive rape investigations in recent years. A verdict is expected in June 2026.
Biography
thumb|Høiby in 2005
Marius Borg Høiby was born on 13 January 1997 at Aker University Hospital in Oslo to Mette-Marit Tjessem Høiby, then a waitress, and Morten Borg. His parents were not in a relationship. At the time of Høiby's birth, Borg was serving a prison sentence for drug‑related violent offences.
From 1997 to 1998, Høiby lived in Oslo with Mette‑Marit and her then‑partner, a disc jockey.
Mette‑Marit married Haakon, Crown Prince of Norway on 25 August 2001, making Høiby Haakon's stepson.
Høiby attended in Oslo. In 2017, he enrolled in business studies in the United States. Later that year, he returned briefly to Norway before working as an intern for designer Philipp Plein. He subsequently worked as a style editor for the UK‑based fashion magazine Tempus until its closure in December 2018.
Høiby has had a series of high-profile relationships. He has dated heiress Linn Helena Nilsen, model and actress Juliane Snekkestad, and influencer Nora Haukland.
Høiby invited members of the Hells Angels criminal gang to events at his home that he called "Skaugum festivals". At these events, Mette-Marit personally received his guests. Drugs were consumed at these events.<!--According to sociologist Trond Blindheim, Høiby "has traveled around as a kind of playboy".-->
In late 2024, Høiby began a programme of drug rehabilitation.
As of 2025, Høiby did not hold a diplomatic passport. In 2024, media stated that he had abused the privilege of holding a diplomatic passport.
Relationship to Norwegian the royal family
When Mette-Marit entered the public spotlight as the girlfriend of Haakon, Crown Prince of Norway, Høiby was nicknamed "Little Marius" by the media. He became known to the public in December 2000, when he appeared in official Christmas photographs of the royal family taken at the Royal Lodge, Holmenkollen. His mother and Haakon announced their engagement later that month. Media commentary at the time focused on Mette‑Marit's background as a single mother and on the fact that Høiby's father had a criminal record, which generated public debate. TV 2 later wrote that "merely by existing, Marius Borg Høiby was seen by many as a scandal for the royal family." and making Høiby Haakon's stepson.
At age four, Høiby served as a page boy at a royal wedding attended by numerous European royals and widely covered by international media.
Høiby is the half-brother of Princess Ingrid Alexandra and Prince Sverre Magnus, his mother's two children with Haakon.
In a documentary filmed during Mette‑Marit's pregnancy with Princess Ingrid Alexandra, Princess Ragnhild, Mrs. Lorentzen expressed concern that Høiby might feel overshadowed once a royal sibling was born.
In 2023, members of the Oslo police organised crime unit reportedly warned Høiby about his cocaine use and his association with individuals known for drug offences.
In 2024, a police interrogation of Høiby revealed that Prince Haakon, "together with the crown princess", paid his bills. Høiby received 20,000 kroner each month.
Because Høiby "is only related to the royal family by marriage, he possesses no royal titles and is outside of the line of succession". He is constitutionally barred from becoming king of Norway.
Legal issues
2017 fine for drug possession
In 2017, Høiby was fined 4,000 Norwegian kroner for drug possession at the Palmesus festival in Kristiansand.
2024 arrests and charges
Throughout 2024, Høiby was arrested and released several times in connection with allegations of violence, drug use, and breaches of a restraining order. A blood test taken while he was in custody indicated recent use of cocaine, ecstasy, and cannabis. Some media outlets claimed that he and his family had received preferential treatment from police, though authorities did not confirm this. with four counts of rape and 34 additional offences, including domestic violence and abuse in intimate relationships. One of the indictments related to allegations made by media personality Linni Meister. Additional charges were filed in early 2026, bringing the total number of counts to 40. One charge relating to a restraining order was later dropped.
Høiby's trial began in Oslo District Court in February 2026. He pleaded not guilty to the rape charges; however, he admitted to some offences, including aggravated assault, reckless behaviour, and transporting marijuana. He remained in custody throughout the trial. An appeals court later upheld his detention during the trial, and he is expected to remain in custody until the verdict. On 6 May, the court disapproved the possibility of Høiby being held in remand on private property during the trial while being electronically tagged; Høiby appealed that verdict. For the counts to which he has admitted, the prosecution sought a sentence of seven years and seven months, with credit for time already served; the defense team asserted that he should be sentenced to one and a half years in prison for those counts.
Mette‑Marit has been accused in the media of warning her son about his impending arrest and of attempting to influence witnesses. In 2026, Høiby testified in court about an interaction with his mother; his testimony gave no indication that she had committed any unlawful act. As late as mid-March 2026, Høiby was visited in Oslo Prison by his mother and his stepfather.
The Høiby case has been described in Norwegian media as one of the most extensive rape investigations in recent years. The case has been cited as contributing to a decline in the Norwegian royal family's reputation and increased debate about the future of the monarchy in Norway.
A verdict is expected in early June 2026.