It is the royal love story that has spanned over 50 years yet has endured such precipitous patches of internal strife and public unpopularity that at times it looked uncertain as to whether it would have a happy ending.
Now, joyously, the relationship between Prince Charles and Camilla, who have been happily married for 17 years, has been given the most spectacular benediction by the Queen. As part of her Platinum Jubilee message to the nation, she has declared her "sincere wish" that Camilla should become Queen Consort when Charles ascends to the throne.
For those of us who remember the War of the Wales's – Prince Charles's divorce from Princess Diana in 1996 - the idea that his mistress, Camilla Parker Bowles, could become Queen for many was unthinkable.
However, in the last 17 years Camilla has earned our deep affection and respect. She has conducted herself with aplomb and sensitivity.
We can see from the couple's tangible happiness together, whether carrying out public duties or being photographed with their dogs, Bluebell and Beth, that they are made for each other. Camilla understands and soothes Charles. Charles never shies away from calling her his "darling" and will be a better King with her by his side.
Perhaps the real tragedy is that Charles and Camilla did not marry the first time around.
Sixteen months older than Charles and the daughter of a British Army Officer, the aristocratic Camilla Shand first met the Prince of Wales when she was 23, at a polo match in Windsor Great Park in 1970.
It is rumoured that Camilla kicked off conversation with Charles in typically robust style. She joked about the fact that her great-grandmother, Alice Keppel, had had an affair with King Edward VII, saying : "My great-grandmother was the mistress of your great-great-grandfather. I feel we have something in common."
Indeed, they had much more in common - an earthy sense of humour, a love of horses, dogs and country pursuits. They began a relationship which was punctured by Charles's eight-month absence when he served in the Royal Navy.
To his bitter regret, in 1973, while he was abroad, Camilla married Andrew Parker Bowles, an Army cavalry officer who had previously dated Princess Anne. Prince Charles, privately heartbroken, remained friends with the couple, becoming Godfather to their son, Tom.
Why didn't Camilla wait for Charles? Perhaps she thought she was acting in his best interests by marrying someone else, aware that as future king, he would be required to marry a virgin.
It wasn't until 1980 that Charles met Diana Spencer, the young aristocratic daughter of Earl Spencer. Diana's grandmother, the formidable Baroness Fermoy, a close confidante of the Queen Mother, pushed this dynastic match.
As we know now, the wedding on July 29 watched by over 750 million people, was not the fairytale it purported to be. Diana was acutely aware that Charles was still said to be in love with Camilla, who was present at the wedding.
Diana found a bracelet that Charles gave to Camilla, entwined with the letters G and F for their pet names, Gladys and Fred, on the eve of her wedding.
After the births of Prince William in 1982 and Harry in 1984, the royal marriage was increasingly unstable. Charles stated in his authorized biography that he rekindled his relationship with Camilla in 1986.
When the story broke in 1992, that Charles had cheated on Diana, vividly detailed in Andrew Morton's book, Diana: Her True Story, Camilla was vilified. Yet, in the face of the most coruscating press, her loyalty to Charles was unparalleled – she stayed silent when it must have been almost unbearably tough for her.
It is especially meaningful that the Queen has spoken out in favour of Camilla, and earlier this year appointed her to the Order of the Garter. In the early nineties, a different mood prevailed. According to Penny Junor, Camilla's biographer, the Queen's trusted aide, Michael Peat, was sent to Clarence House to "deal" with the Camilla situation.
The Queen liked Camilla personally, but her presence was seen as threatening monarchical stability. However, after Michael arrived he came to a rather different conclusion. As Junor says he saw "that Camilla was the secret weapon. In no way should Charles have given her up because she managed him so well."
Those were dark days to negotiate for the couple. Nothing was more excruciating than the tabloid transcript in 1993 of the 'Camillagate' taped late night conversation between Camilla and Charles.
Meanwhile "Diana was great at painting the picture of the damning Rottweiler, as she called Camilla," says Junor. There was the apocryphal story that Camilla was pelted with bread rolls in a supermarket car park. "That never happened," sighs Junor. "It's one of the great myths but figuratively she has been hit with many bread rolls."
After the Princess' death, Charles and Camilla faced their bleakest time; their relationship was regularly erroneously blamed for Diana's tragic demise. It was in January 1999, that Charles publicly outed Camilla as his partner, standing on the steps of the Ritz, after he had hosted a 50th birthday party for her sister, Annabel Elliot. A petrified Camilla faced a phalanx of flashbulbs. That summer, she and Charles holidayed in Greece with, significantly, Princes William and Harry.
By the time of their marriage in 2005, 35 years after they first met, they had secured the Queen's blessing. Our monarch gave a moving speech at their Windsor Castle wedding reception, welcoming her son and his bride to the "winners enclosure."
Ever since a nervous Camilla stepped out in Windsor, exquisitely understated in oyster silk on her wedding day, we have witnessed a genuine case of love conquering all. The Duchess of Cornwall has proved herself to be a light-hearted asset. She emanates ease, allowing us a sense of her true self. Her guileless mirth is contagious. Sometimes on official visits, Camilla is literally clutching herself as she tries to stem hopeless giggles. Robert Johnson, the American ambassador, calls her "a riot".
Camilla is gloriously unneurotic. Their relationship works because she lightens her husband's more eeyore tendencies. She's not prone to introspection or self-pity. With their shared love of nature, they have matured from the young couple in their twenties, to a devoted couple in their seventies who understand and, more crucially, enjoy each other.
The woman who once looked set to derail the House of Windsor is now poised to secure its future stability.