The Aussie set to become Queen of Denmark

Denmark's popular Australian-born Crown Princess Mary will cap a real-life fairytale Sunday when she becomes queen after her husband Crown Prince Frederik accedes to the throne.

The glamorous 51-year-old is credited with helping modernise the Danish monarchy over the years, and is one of its most popular members.

Queen Margrethe II shocked Danes when she announced her plans to abdicate after 52 years on the throne in her annual New Year's Eve speech, citing her age -- 83 -- and health issues.

The future queen, born Mary Donaldson, brought a breath of fresh air to the monarchy and dazzled Danes when she married into the royal family.

"Some people think my husband is a bit in my shadow because I'm very much in the spotlight and I have a lot of engagements," she said in a 2017 authorised biography of Prince Frederik.

"But he'll never be in my shadow, and I'll never be in his shadow, because he reflects light on me," she said.

Born in Hobart, Tasmania on February 5, 1972, Mary was working as an advertising executive in Australia when she met the then 34-year-old Frederik while out with friends at Sydney's Slip Inn bar during the summer Olympics in 2000.

She only discovered later that he was the crown prince of Denmark and his group of friends was made up of other European royals -- including his younger brother Prince Joachim and cousin Prince Nikolaos of Greece and Denmark.

"The first time we met, we shook hands," she said in an interview several years ago.

"I didn't know he was the prince of Denmark. Half an hour later, someone came up to me and said, 'Do you know who these people are?'"

Frederik meanwhile told daily Kristeligt Dagblad that meeting Mary was "not only a rush of love, but also the feeling of having met my soulmate."

After a discreet long-distance relationship and numerous under-the-radar visits, the couple became officially engaged in October 2003 and married on May 14, 2004 in Copenhagen Cathedral.

They are now parents to four children: Prince Christian, 18, who will one day succeed his father as king, Princess Isabella, 16, and twins Prince Vincent and Princess Josephine, 13.

- Modern and trendsetter -

Mary made a splash in Denmark from the start, impressing Danes with her ability to learn the Danish language quickly.

She also won over her mother-in-law immediately.

"I have to say that the first time (Frederik) allowed me to meet her, I hoped it would last," Queen Margrethe recalled in a 2015 interview.

A poll published by Danish television TV2 in December declared Mary Denmark's third-most popular royal, behind the immensely popular queen and Frederik.

"For the almost 20 years that she has been a member of the royal family, the crown princess has widened and perfected her role as spokesperson and PR official for the royal family, Denmark, and her chosen causes," the daily Berlingske wrote recently.

She is often compared to Britain's Princess Catherine for her sense of style and long dark locks, regularly making the fashion pages of Danish and international magazines.

She is also known for her work to fight bullying, domestic violence and social isolation, as well as promoting mental health and women's rights.

Mary and Frederik are considered a modern couple, who love pop music, modern art and sports, according to historian Sebastian Olden-Jorgensen.

They have tried to give their four children as normal an upbringing as possible, sending them mainly to state schools.

Their first-born, 18-year-old Prince Christian, was the first Danish royal to attend daycare.

They "do not represent a potential revolution compared to the queen", but a careful transition adapting to the times, Olden-Jorgensen said.