He was just seven months old when his father was killed in a car crash.
This made him heir to his grandfather, King Gustaf. King Carl Gustaf has talked of the sadness of growing up without knowing his father.
What emerges is a monarch who has spent a fortune on sex parties and strip clubs.
At one Stockholm club elaborate dinners were followed by liaisons in a communal whirlpool with scantily clad women, some of them, it seems, aspiring models.
He said that a prime minister who couldn’t take care of baby seals couldn’t be very good at taking care of his country.
First, their son Prince Carl Philip ended a decade-long romance with his girlfriend and started seeing Sofia Hellqvist, a reality TV show model who has posed wearing nothing but a python and a G-string.
Then it emerged their younger daughter Princess Madeleine, 28 — once seen as a possible bride for Prince William — had pulled her engagement ring off her finger, cancelled her wedding to her dashing lawyer boyfriend of eight years, Jonas Bergstrom, and flown in tears to New York, where she remains.
Several women interviewed for the book claim they had sex with the King.
Indeed, after one big dinner celebrating a successful elk hunt, he is said to have enjoyed sex with two women at the same time.