King Haakon begins reign with Princess Ingrid Alexandra taking key step beside him

King Haakon has formally ushered in a new era for Norway after taking the constitutional oath following the death of his father, King Harald.

The new monarch swore to govern the Kingdom of Norway “in accordance with its constitution and laws” during a historic ceremony at the Storting in Oslo.

The King took the oath at 12.06pm local time, reading from a book while seated on a golden throne. 

Standing beside him was his 22-year-old daughter, Crown Princess Ingrid Alexandra, in a moment that offered a striking glimpse of both the present and future of the Norwegian monarchy.

Ingrid Alexandra signed her own constitutional oath at the Royal Palace later that afternoon.

The Princess is required to take the oath so that she can, in the future, carry out certain constitutional duties in her father's absence, including acting as Regent and leading meetings of the Council of State when required.

The document signed her carries the same solemn promise made by her father: “I promise and swear to govern the Kingdom of Norway in accordance with its constitution and laws, so help me God the Almighty and the All-Knowing.”

It was also the first time an heir over the age of 18 had accompanied a reigning monarch for the constitutional oath.

The King then spoke of the responsibility now facing him, saying that he and Queen Mette-Marit were ready to serve Norway.

“The Queen and I confirm that we are available to carry out our duty for the country and the people,” he said.

The ceremony followed arrival at the Royal Palace, with King Haakon travelling in an open 1966 Lincoln Continental.

He was joined at the palace by Queen Sonja, Crown Princess Ingrid Alexandra and Prince Sverre Magnus before travelling to the Storting.

One notable absence was Queen Mette-Marit. The palace confirmed on Monday morning that she would not attend.

After Haakon took the oath, the President of the Storting delivered a memorial speech in honour of the late King Harald.

A minute's silence followed before the royal anthem was played.