But the Grimaldis are all grown up now. Prince Albert II and his lawyers have resolved the paternity suits that dogged him, acknowledging fatherhood of a boy and a girl born to different women. Princess Caroline has settled down with a German prince. Even Princess Stephanie has dropped off the society pages.
During a recent interview, Albert, 49, now in charge of the principality, reflected on the event that helped send him and his sisters into their difficult years: the sudden death of their mother, the former Grace Kelly, whose wedding to Prince Rainier III of Monaco took place in the days before the news media made public fodder of royalty's private indiscretions.
"It's obvious that it was difficult for all of us," the prince said. "It took me a while to get over it and try to help my family, help my father as much as possible."
Now, 25 years later, the children are commemorating their mother's life by exhibiting some of her most personal possessions. Hundreds of objects, from letters to dresses, go on display here next week. A separate, smaller exhibition will travel to Sotheby's in New York in October.
Princess Grace was 52 on Sept. 13, 1982, when she careered off a hairpin turn while driving to the palace from the family's mountain retreat, Roc Agel. Her green Rover tumbled 120 feet before coming to rest upside down. She died the next day.
"She had just left the family property, and I was still up there and I had seen her because she came in to my room to try and get me out of bed," Albert recalled. "I was still having breakfast when we heard the news from my father."
The death was hardest on Stephanie, who was also in the car. She was 17 and had been locked in a battle with her mother over her affair with Paul Belmondo, race-car driver and son of French actor Jean-Paul Belmondo. She survived with minor injuries.
"Coming to terms with her being in the accident was very instrumental in, well, in her difficult years after that," Albert said. "We all underestimated . . . the trauma that she went through."
The news media speculated for years that an argument had distracted Grace and caused the accident, or even that Stephanie herself was at the wheel. The reality was far more banal: Doctors concluded that Grace had suffered some sort of attack, most likely a minor stroke.
Both Albert and Caroline also seemed to lose their bearings. He ran through women like water, impregnating at least two. She, with one failed marriage behind her, lost her second husband in a speedboat accident in 1990 and then married Prince Ernst August of Hanover, who made a name for himself with drunken, boorish behavior.
Now, with their father gone (he died in 2005), Albert on the throne, and scandal behind them, the children decided it was time to look back on the legacy of their Philadelphia-born mother, including her film career.
"There were going to be some other people trying to commemorate her memory in different ways, so we thought it would be the most opportune time to celebrate her life," Albert said.
He and his sisters selected hundreds of items from among Grace's possessions for display beginning next Thursday at the Grimaldi Forum conference center.
"It was very much a family process," the prince said, adding that he hadn't seen many of the things since he was a child. "It wasn't a painful process. It was an emotional one, but a joyful one."
The items include the very personal - a poem Princess Grace wrote as a gift for Albert on his 18th birthday and home movies never shown outside the family. But there are also mementos of her public life, letters from Alfred Hitchcock and from Jacqueline Kennedy, for example.
Visitors will see the gown Grace wore in what was called at the time "the wedding of the century." Among other dresses on display will be one she wore in the 1956 film High Society - her last before becoming a princess - and the one she wore when she accepted an Oscar in 1955 for her performance in The Country Girl.
Albert said he hoped the exhibition would help keep memories of his mother alive for a new generation. There are more than sentimental reasons for doing so: The glamour she brought with her from Hollywood helped revive Monaco's flagging fortunes after the war, and the fairy-tale fantasy is equally important in keeping the principality attractive as a convention and tourist destination.
As her only son and the heir to the throne, Albert was particularly close to his mother, while his father was famously distant. "Sometimes there's a very special relationship between a mother and her son," he said.
"She did say that I have good instincts and that I should try to follow them," he added.