A timeline of Prince Charles and Camilla Parker Bowles' controversial, long-lasting relationship

The Privy Council of the United Kingdom is a group of the queen's most senior advisors, so Camilla's addition was a great honor.

Most reports agree that Camilla and William were granted access to the council to ensure that they will both be present in the event that Charles ascends the throne.

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The month before their anniversary, Charles spoke highly of his relationship with Camilla in an interview with CNN.

"It's always marvelous to have somebody who, you know, you feel understands and wants to encourage. Although she certainly pokes fun if I get too serious about things. And all that helps," he said.

In 2012, Camilla was granted the title of Dame Grand Cross of the Royal Victorian Order from the queen.

Later that year, Camilla rode alongside her during the Diamond Jubilee — which celebrated the queen's 60th anniversary as monarch.

On the 10-year anniversary of Diana's death, the royal family held a memorial service at Buckingham Palace.

Camilla was invited to the service, but she decided that it was best if she didn't attend.

According to CNN, she said in a statement, "I accepted and wanted to support them, however, on reflection I believe my attendance could divert attention from the purpose of the occasion which is to focus on the life and service of Diana."

About 35 years after their first meeting, the prince and the Duchess of Cornwall were married in a civil ceremony at Windsor Guildhall.

Although the queen and her husband, Prince Phillip, were not in attendance at the ceremony, they came to the reception at Windsor Castle, according to The Sun.

The longtime couple announced their engagement on February 10, 2005, immediately fueling speculation about Camilla's new title.

Many wondered if she would be known as queen or princess consort in the event that Charles ascended the throne, and whether she would take the title of Princess of Wales (the name given to the late Princess Diana) in the meantime.

Sidestepping any potential controversy, Buckingham Palace confirmed that the queen was gifting her new daughter-in-law the title of Duchess of Cornwall and that she'd be known as princess consort, not Queen Camilla, if Charles became king.

Camilla and Charles moved into Clarence House together in the summer of 2003.

According to The New York Times, in 2000, the queen accepted an invitation to the King of Greece's 60th birthday party held at Highgrove. As she knew that Camilla would be there, her gesture was seen by many as a tacit acceptance of the relationship.

It appeared that William and Harry were starting to warm up to their future stepmother in the summer of 1999.

According to the BBC, the foursome took a trip to Greece, which seemed to signal that things were becoming more serious with the couple.

Camilla and Charles started 1999 off on a fresh foot as they took their relationship public for the first time. The pair were photographed leaving Camilla's sister's birthday party at the Ritz Hotel.

After the public's emotional response to Diana's passing, Camilla and Charles kept their relationship out of the public eye. However, they were still trying to get the royal family to warm up to it.

William reportedly met Camilla for the first time in 1998, though Harry did not come along to the initial introduction.

Later that year, as the Los Angeles Times reported, the queen was notably not in attendance at Charles' 50th birthday. Many perceived as a snub toward her son's relationship since Camilla was at the event.

Nearly a year after the former couple signed their divorce papers, Diana died after a car crash in Paris.

Amidst the outpouring of public grief and mourning, Charles traveled to Paris to bring Diana's body back to England, and temporarily put his campaign to publicly introduce Camilla as his girlfriend on hold.

After his divorce from Diana was finalized, Charles began trying to endear Camilla to the public and to his family.

Doing so included hosting a lavish 50th birthday party for her at his home of Highgrove, the Associated Press reported. Diana was reportedly not invited.

Charles and Diana made their divorce official in the summer of 1996.

The announcement of Camilla and Andrew Parker Bowles' planned divorce set off a media firestorm with reports that Charles and Diana were next.

According to The New York Times, following months of speculation, Prince Charles finally admitted to being unfaithful during an interview with documentary filmmaker Jonathan Dimbleby.

When Dimbleby asked him if he was "faithful and honorable" during his marriage to Diana, he said, "Yes, absolutely. Until it became irretrievably broken down, us both having tried."

Although he didn't specifically name Camilla as his lover, he called the other woman "a great friend of mine," and someone who "will continue to be a friend for a very long time."

Later, Dimbleby's biography of the prince, titled "The Prince of Wales: A Biography," confirmed that Camilla was the woman in question.

Shortly after "Camillagate" made headlines, Prime Minister John Major confirmed that the Prince and Princess of Wales had formally separated.

Their split raised questions about Charles' future relationships because he was not permitted to divorce and remarry in the Church of England at that time.

In the winter of 1992, an intimate transcript of a 1989 phone call between Charles and Camilla was released to the public.

They talked, among other things, about Charles being transformed into a pair of her "knickers" or her tampon because Charles said, "I'll just live inside your trousers or something. It would be much easier."

The scandal was dubbed "Camillagate" by the press.

In the 2017 documentary "Diana: in Her Own Words," archival footage showed that Charles and Diana's relationship turned rocky soon after their wedding because of Charles' close relationship with Camilla.

According to Sally Bedell Smith's biography of Prince Charles, he and Camilla reportedly began having an affair in 1986.

And, per Penny Junor's book "The Duchess: Camilla Parker Bowles and the Love Affair That Rocked the Crown," Andrew Parker Bowles was well aware of the infidelity and did nothing to stop it.

Diana also reportedly knew about the affair, according to royal biographer Andrew Morton's interview with the princess.

When Prince Harry was born, Charles was reportedly slightly disappointed because he wanted a girl.

According to Good Housekeeping, Diana's biography "Diana: Her True Story — in Her Own Words" said that she knew her whole pregnancy that she was carrying a boy, but she refrained from telling Charles because she knew he would be disappointed.

Charles and Diana welcomed their first child, Prince William, about a year after their wedding.

By this time, Camilla and Andrew Parker Bowles had already welcomed two children — Thomas and Laura.

Diana and Charles were married in a fairytale ceremony that, at the time, was called "the wedding of the century."

The pair met in November 1977 when Diana was 16 years old and Charles was dating her older sister.

Charles and Diana began dating in July 1980 and only met up 13 times before Charles proposed the next year.

In the years after the Parker Bowles tied the knot in July of 1973, she and her husband developed a close friendship with Charles, according to People magazine.

Charles was even named godfather to the Parker Bowles' first son, Thomas.

While Charles was away in the Royal Navy, Camilla accepted the proposal of an army cavalry officer named Andrew Parker Bowles.

Charles and Camilla reportedly met for the first time at a Polo match at Windsor Castle in 1970, setting the stage for an on-and-off relationship that would span the next five decades.

Although the pair appeared to be smitten, Prince Charles' service in the Royal Navy, which began in 1972, put an end to their fledgling romance.