Who is Marius Borg Hoiby? Norway's crown princess's son sentenced to 4 years

Marius Borg Hoiby, the 29-year-old son of Crown Princess Mette-Marit of Norway, has been sentenced to four years in prison following a verdict by the Oslo court.

The court found him guilty of two counts of rape.

He was born on January 13, 1997, in Kristiansand, Norway, and is the son of Crown Princess Mette-Marit of Norway and her ex-boyfriend, Morten Borg. 

His half-brother and sister are Princess Ingrid Alexandra, who is the apparent heir to the throne of Norway, and Prince Sverre Magnus.

Høiby studied at WANG Toppidrett Oslo from 2013 until 2016, and has also enrolled in Santa Monica College, which is based in California, in 2017. 

When his mother married Crown Prince Haakon in 2001, Høiby had already attained the age of four years. Nevertheless, Høiby does not bear any royal title and is not part of the royal succession.

Inside the rape trial

Hoiby was first arrested in August 2024 in Oslo’s Frogner district after a domestic assault. Police later expanded the scope to 32 charges, eventually increasing to 40 charges.

Charges included four counts, including r*pe, drug offense, and traffic violations.

In June 2025, his case was forwarded to prosecutors, and an official indictment followed in August 2025. His trial lasted for seven weeks, starting on February 3, 2026. 

Prosecutors sought seven years and seven months in addition to 580,000 kroner ($60,840) in compensation.

For now, Hoiby plans to appeal.