When he was posted aboard on naval service, Charles didn't ask his girlfriend to wait for him.
So she went on to marry – and have two children with – long-standing admirer Andrew Parker Bowles.
The two remained friends, however. Charles was godfather to Camilla's son Tom, born in 1975.
The heir to the throne continued to see his ex and her new husband on the social scene and polo circuit.
While Camilla got settled into family life, Charles found love again with Lady Diana Spencer, whom he went on to marry in July 1981.
To please Charles for whom she still had a great regard, Camilla befriended the new Princess of Wales.
But both their marriages fell into difficulty - Camilla divorced in 1995, Charles the year after.
There was controversy when Charles admitted he had indeed begun seeing Camilla romantically while still married.
He confirmed in a televised interview that their relationship resumed after his marriage had "irretrievably broken down" in 1986.
Supporters of the Princess also compared Camilla unfavourably to fashionable Diana - overlooking the fact that her life as a country housewife really didn't require a glamorous wardrobe.
Following the tragic death of Princess Diana in 1997, the lovers decided to keep a low profile because of sensitivities to the public mood.
Two years later, however, the couple made their first public appearance together at a party in London's Ritz Hotel, greeted by hundreds of photographers.
A sleeker, more polished image also emerged for Camilla in keeping with her role as the Prince's companion.
Charles; plus one adopted a more flattering hairstyle with blonde highlights and a couture wardrobe mostly of Robinson Valentine outfits.
Then in 2002 it became evident they were ready to move further into the spotlight when the first picture emerged of them holding hands.
A former aide of the Prince's Mark Bolland explained what Camilla felt about her public image.
"She's a lovely woman – kind and patient. She has no desire to be famous, or popular," he said. "What she doesn't want is to be hated."
He added: "The period when she was demonised and traduced by newspapers was very upsetting for her, and it upset him [Charles] enormously too, because he felt responsible for it."
Charles made it be known that their relationship was "non-negotiable".
His love was still in an uncomfortable no man's land, however.
Here at a Golden Jubilee concert for the Queen that year, she is seated to the left in the row behind the senior royals.
Three years later came the news many royal watchers had been waiting for. Charles and Camilla were engaged to be married.
Charles presented his intended with a unique art deco style ring featuring a huge square cut diamond flanked by three diamond baguettes.
The family heirloom was reportedly given to the Queen Mother in 1926 on the occasion of the birth of her daughter, Queen Elizabeth.
After two months of preparation and what seemed like a lifetime of waiting, Camilla and Charles married in a civil ceremony in Windsor.
This was followed by a blessing, for which the bride wore elegant in a Philip Treacy hat and full-length porcelain blue silk Robinson Valentine dress with a hand-painted ikat design, hand-embroidered with gold threadwork.
Camilla had been accepted at the heart of the monarchy.
And by the public. The newlyweds were overjoyed.
During the toast, guests reported that Charles shouted: "I love Camilla" as he raised his glass.
Their wedding gave her a new title - the Duchess of Cornwall. She would not be styled the Princess of Wales out of respect for the late Diana.
The Duchess has been credited with bringing a joie de vivre to the couple's shared life. The pair are frequently pictured in giggles on public engagements.
Always game in any situation, Camilla lightens the burden of her husband's royal duties.
She has become a mentor to the younger members of the family.
Harry summed up the affection for her within the Windsor clan when he said: " We are very grateful for her. She's made our father very happy."
The Queen also finds her daughter-in-law a great support.
No can anyone claim any longer that she is not a fittingly regal consort for her Prince.
In Camilla, Charles has found his soulmate and equal.
A witty and intelligent woman, she shares his love of outdoor life and never fails to bring a smile to his face.