Princess Ingrid Alexandra of Norway marks 20th birthday with unusual celebration - details

Norway's Princess Ingrid Alexandra turned 20 on Sunday but it will be a very different birthday from her usual celebrations. While she may still mark the day, she won't spend it enjoying a party or with her parents and grandparents as she typically does.

Instead, the young royal will be in a very different environment as she continues her military service, which began on Wednesday at the Skjold camp, part of the Northern Brigade of the Norwegian Army, and will continue for the next year.

During her training, she will learn hand-to-hand combat among other skills and will live alongside an estimated 800 soldiers and 200 civilian employees.

Although they couldn't be with her on her special day, the Norwegian royal family's social media accounts paid tribute to the princess, including with one photo that showed her wearing her military uniform, which was captioned: "Happy birthday to Princess Ingrid Alexandra who turns 20 today."

Another image showed Ingrid performing military manoeuvres alongside fellow soldiers in training, with a caption that read: "The princess has begun her first service serving in the engineer battalion at Camp Skjold in Indre Troms." It's the latest move towards independence for the princess, who is the daughter of the heir to the throne Crown Prince Haakon and his wife, Crown Princess Mette-Marit.

Last October, the princess moved out of the family's royal residence, Skaugum, and into a flat in Oslo, according to local media.

Norwegian publication Se og Hør reported at the time that Ingrid, who is second-in-line to the Norwegian throne after her father, had chosen the hipster area of Grünerløkka for her new abode.

Close to the city centre, Grünerløkka is dubbed one of the city's coolest neighbourhoods and as Vogue noted: "Simply put, Grünerløkka is where you want to be next time you're in Norway."

You may also like

• Royal heirs pictured on their milestone 18th birthday

• Princess Ingrid Alexandra ticks off daring challenge from personal bucket list

The area is known for its street art, stylish bars, nightclubs, hipster cafés, live music venues, and boutiques selling vintage clothing, while picturesque walking trails follow the Akerselva River.

Ingrid graduated from the Elvebakken Upper Secondary School in Oslo last April before working as a school assistant and environmental worker at one of her old schools, Uranienborg School, also in the capital. Her military training sees her follow in her father's footsteps.

While Ingrid may have flown the nest, however, her younger brother Prince Sverre Magnus, 18, is still living at the family home in Asker as he completes high school at Elvebakken Upper Secondary School.

The Norwegian royals were among the guests who attended now-Crown Prince Christian of Denmark's 18th birthday gala in Copenhagen last year. Royal watchers were thrilled to see Crown Princess Mette-Marit on good form as she returned from a period of sick leave, looking radiant in an ice-blue satin gown.

Ingrid was equally stunning in a one-shoulder pleated gown in the same ice blue as her mother's. She wore the Boucheron pearl circle tiara and the Order of the Elephant for the first time – a Danish order of chivalry and Denmark's highest-ranked honour.

Listen to HELLO!'s A Right Royal Podcast and find out why a reconciliation between King Charles and Prince Harry is set to happen...