Who is the future king of Denmark?

That moment came on January 1, when the Queen of Denmark unexpectedly announced her abdication in the middle of this month and gave the throne to her son.

"Rebellious" adolescence

"He was not a rebel, strictly speaking, but throughout his childhood and young adulthood he was very uncomfortable with the media attention and the idea of becoming king," said Gitte Redder, an expert on the Danish royal family.

He only “got his confidence in his 20s,” Ms Redder said.

But Frederik - who speaks English, French and German - only really began to mature after training in three branches of the Danish military.

The Queen's Complement

"He's a sports person, he attends concerts and football matches. That makes him even more approachable than his mother," said royal expert Redder.

He met his wife, Australian lawyer Mary Donaldson, in a Sydney bar during the 2000 Olympics. They have tried to give their four children as normal an upbringing as possible, sending them mostly to public schools.

The couple are "modern, into pop music, modern art and sports," according to Mr Olden-Jorgensen.

They “do not represent major changes from the queen,” but rather a careful shift to adapt to the times, according to expert Olden-Jorgensen.

"Mother paints, I exercise. Mother digs for buried objects, I bury my head to avoid being recognized during my time in the army. Mother is a master of words. I sometimes find it hard to understand them," he joked at the Queen's 50th anniversary celebration.