They first met at a Windsor polo match in 1970 and came across each other again in June 1972 at a London club.

It was clear the heir to the throne was keen on country-loving hunting fan Camilla from the start, especially when she jokingly mentioned that her maternal great-great-grandmother, Alice Keppel, was the long-time mistress of Charles's great-great-grandfather, Edward VII.

Mrs Parker Bowles - then Camilla Shand - is said to have told the prince: "My great-great-grandmother was your great-great-grandfather's mistress, so how about it?"

The two became very close but the relationship cooled when Charles joined the Royal Navy in 1971. Two years later Camilla married her long-standing admirer, Army officer Andrew Parker Bowles.

Throughout the late 1970s Charles and Camilla kept up contact and became close again towards the end of the decade.

However Camilla did play a part in encouraging the match between Charles and Lady Diana Spencer, and it is thought the prince proposed to Diana in the Parker Bowles's vegetable garden.

After his marriage, in July 1981, Charles remained close to Camilla. Diana was intensely jealous of her husband's relationship with her and quizzed his aides about it constantly.

Royal watcher Andrew Morton named Camilla as "the other woman" in the Prince's life and said the Princess referred to her as "The Rottweiler".

It is thought that after Charles and Diana drifted further and further apart, following the birth of Prince Harry in 1984, he eventually returned to his old flame.

The depth of their intimacy became clear in 1992 when the so-called "Camillagate" tape surfaced, in which Charles was caught saying he longed to be Camilla's tampon.

In the recording of a telephone conversation between the two, made in December 1989, Charles said: "I love you" to Camilla and added many other highly personal endearments.

Camilla has consistently maintained a dignified silence about her friendship with Charles, who said of her in the 1994 Jonathan Dimbleby TV documentary: "Mrs Parker Bowles is a great friend of mine ... a friend for a very long time.

"She will continue to be a friend for a very long time."

When the prince admitted he had committed adultery after his marriage to Diana had broken down, Mrs Parker Bowles was widely assumed, but never confirmed, to be the other woman involved.

Diana later went on television to say there had been three people in the marriage and it had been too crowded.

Camilla was now recognised everywhere and her comfortable, country-set life was turned upside-down. Women threw bread rolls at her in a supermarket as she faced a public backlash. Camilla had become "the marriage-wrecker".

She and Andrew Parker Bowles, a former Silver Stick-in-Waiting to the Queen, divorced in 1995 and Camilla became a regular visitor to the Prince's Gloucestershire home, Highgrove.

In April 1997, Camilla took a tentative step into public life when she became patron of the National Osteoporosis Society. An official photograph was released to mark the occasion.

In July that year, Charles hosted a party for Camilla to celebrate her 50th birthday. She was pictured arriving at Highgrove by car.

The idea of Charles and Camilla as a couple was gradually being officially introduced to the public.

But the tragic death of Diana in August 1997 in a car accident changed everything. A charity function planned for September, at which the Prince and Camilla may have appeared together, was cancelled.

Public opinion, royal advisers thought, would not countenance the idea of Camilla replacing Diana.

However, in 1999 Camilla met Prince William and Prince Harry for the first time, and the teenagers and she later hosted a glittering party at Highgrove for 200 guests to celebrate Charles's 50th birthday.

In recent years, she has regularly accompanied Charles to Prince's Trust galas and became accustomed to donning an evening gown and sparkling jewels and appearing in front of the media.

As Clarence House was renovated and Camilla became the prince's live-in partner, questions began to surface about the cost of her lifestyle.

In June 2004, Mrs Parker Bowles appeared for the first time in the prince's official accounts - moving her into a new realm of official acceptance.