But it was his compassion that ultimately helped him connect with his 10 million subjects, many of whom are expected to take part in weekend festivities in his honour.

The king’s finest hour came in January 2005, shortly after more than 500 Swedes lost their lives in the tsunami that swept across tourist resorts in southeast Asia.

“What if I, just like the king in the fairytales, could make everything all right and end the story with ‘And then they all lived happily ever after’. “But I, just like you, am only a grieving, searching, fellow man,” he said in a speech that hit the right note when the Swedish government’s response was seen as lacking.

Despite being a hesitant public speaker, the king opened up about losing his father without ever knowing him, winning praise from victims’ families and the public.

Born on April 30th, 1946, Carl Gustaf Folke Hubertus Bernadotte was only nine months old when his father, Prince Gustaf Adolf, was killed in a plane crash in Denmark.

Sex scandals

He became crown prince at four when his grandfather ascended the throne as King Gustaf VI Adolf in 1950 and then king in 1973. For the 27-year-old, who had grown up with four older sisters and an often-absent mother – Princess Sibylla of Sachsen-Coburg-Gotha – it was “simply very tough” to become the world’s then youngest king, he later confided.

“I don’t think one can ever quite understand what such a task entails on a personal level,” he told Swedish Radio in a 2013 interview. Speaking in his first podcast aired just before his 75th birthday, he called his job “draining”.

The king – who occasionally appeared shirtless in gossip magazines in his early years as monarch – has never quite managed to shake his playboy image.  And subsequent sex scandals only reinforced that.

Yet the monarchy has been broadly popular under “Carl Gustaf”. He married a German-born commoner, interpreter Silvia Sommerlath, three years his senior, in June 1976. The couple, who met during the 1972 Munich Olympics, went on to have three children: Crown Princess Victoria, Prince Carl Philip and Princess Madeleine.

Victoria (born July 14th, 1977) is expected to succeed him, becoming Sweden’s first reigning queen in nearly 300 years.

In 2019, the king slimmed down the royal household, stripping the children of his two youngest offspring of their “His/Her Royal Highness” titles. His grandchildren retain their prince and princess titles but will not receive an appanage.

Passion for cars…

Carl XVI Gustaf’s passion for luxury cars is well documented. A collection of vintage American models share garage space with Swedish classics and European sports cars at his lakeside castle outside Stockholm.

He has passed his interest on to his son – though he was unable to pass him the crown. In January, the king reiterated his criticism of Sweden’s 1980 change of succession laws to make the first-born child monarch – in his case his daughter Victoria.

It meant his then seven-month-old son Carl Philip’s lost his title as crown prince. The king, who is barred from meddling in political affairs, called the move “unfair”, which didn’t go down well in gender equal Sweden.

…and women

In 2010, a book on the king’s private life alleged he was a philanderer and a regular at sex clubs in the 1990s, repeating previous claims he had numerous affairs with younger women.

The controversial book – titled The Reluctant Monarch – took a toll on the king’s popularity, especially because he never denied the claims outright. The king told reporters he had discussed the book with his family, who were hurt by the allegations. “Now we’re turning the page,” he said.

The press also often teased him for his many gaffes, including misspelling his own name at a 1973 signing. It later emerged he suffered from dyslexia, as do two of his children.

A keen sportsman and hunter, the king has taken part in the gruelling 90-kilometre (56-mile) Vasaloppet cross-country ski race three times. Not known to have any major health concerns, he underwent keyhole heart surgery in February 2023 that went “according to plan”, the palace said.

Passionate about the environment, he chairs the Swedish branch of the World Wide Fund For Nature and is honorary chairman of the World Scout Foundation.