Real story behind The Crown's 'love quadrangle' - Princess Anne, Camilla, Andrew Parker Bowles and Prince Charles

So what are the real-life events behind the Netflix drama? Here's what you need to know:

How did Prince Charles meet Camilla?

By the time Camilla Shand and Prince Charles were formally introduced, the two of them were already moving in the same social circles and attending some of the same events; Camilla had been dating Charles's fellow polo-player Andrew Parker Bowles, but their relationship ended (temporarily) in 1970.

It's commonly thought that Charles and Camilla met at a polo match, but biographer Gyles Brandreth says they actually met at the home of their mutual friend, Lucia Santa Cruz. Whatever the case, we do know that they soon began a romantic relationship.

Camilla, who is 18 months older than Charles, was born to Major Bruce Shand and Rosalind Cubitt – the daughter of a baroness. She was educated in England, attended a finishing school in Switzerland, and briefly studied in France. Like many of the upper-class set, she developed a passion for horse-riding; by the time we meet her in season three of The Crown (where she's played by Emerald Fennell), Camilla is in her early 20s and hanging out in London.

Once she and Charles got together, they met regularly at polo matches and socialised as a couple; they also met each other's families and seemed to be getting serious.

Did Princess Anne date Camilla's ex-boyfriend, Andrew Parker Bowles?

In The Crown, we see Andrew Parker Bowles (Andrew Buchan) and Princess Anne (Erin Doherty) flirting at a party – and then we see Anne enjoying a post-coital Bloody Mary in bed while Andrew wanders around topless.

The storyline has surprised many fans of The Crown, but it hasn't come out of nowhere! After breaking up with on-off girlfriend Camilla, Andrew did have a brief relationship with Princess Anne – and seeing as Camilla then got together with Anne's older brother Prince Charles, it all turned into a bit of a love 'quadrangle'.

Some have speculated that Camilla's interest in Charles may have been retaliation against her ex-boyfriend – at least, initially. That's the version of events hinted at in The Crown.

Either way, the relationship between Andrew and Anne never got really serious. He did accompany the Princess during Royal Ascot Week one year, but it was unlikely to progress much further for them; Andrew was Catholic, and Anne's mum was the head of the Church of England, so she couldn't marry him without renouncing her right to the throne.

Nevertheless, Andrew and Anne remained friends even after they both married other people – with Andrew even becoming a godfather of Princess Anne's daughter, Zara.

In 1973, Anne married Mark Phillips. They divorced in 1992, and in the same year she married her second husband: Timothy Laurence, who had previously served as her mother's equerry.

Did the royal family try to stop Camilla and Charles from marrying?

It's hard to say for certain, but it seems Charles's family did get involved.

Following royal tradition, Charles had signed up for military service in 1971, remaining with the Royal Navy and Royal Air Force until 1977. During this time he trained as a jet pilot, was sent to the Royal Naval College Dartmouth, and then served on a guided missile destroyer, two frigates and an aircraft carrier. So, in early 1973, he found himself sent overseas.

At this point, his relationship with Camilla was put on hold – and then came to an abrupt end when Camilla accepted a marriage proposal from Andrew Parker Bowles, her on-off boyfriend of around seven years. They married in July of the same year.

So, did Lord Mountbatten (played by Charles Dance) and the Queen Mother (played by Marion Bailey) conspire to split Charles and Camilla up and prevent their marriage?

One possibility, as suggested by Robert Lacey in his 2008 book 'Royal', is that Charles had failed to ask Camilla to wait for him when he went overseas with the Navy. Perhaps Charles wasn't ready to commit to marriage, considering himself too young; perhaps the simple truth is that Camilla preferred to marry Andrew.

The other possibility, suggested by Sarah Bradford in her 2007 biography of Princess Diana, is that Charles's great-uncle Mountbatten (a powerful and well-connected military man) arranged for Charles to be taken overseas to sever that relationship with Camilla.

After all, Lord Mountbatten wasn't impressed with the idea of a woman like Camilla marrying the heir to the throne. In February 1974, when it was all over, he wrote to Charles: "In a case like yours, the man should sow his wild oats and have as many affairs as he can before settling down, but for a wife he should choose a suitable, attractive, and sweet-charactered girl before she has met anyone else she might fall for ... It is disturbing for women to have experiences if they have to remain on a pedestal after marriage."

In Mountbatten's eyes, getting rid of Camilla might pave the way for an engagement to a more 'suitable' woman: ideally Amanda Knatchbull (Mountbatten's pick, who also happened to be his own granddaughter), or one of the Spencer sisters (the Queen Mother's pick).

In support of the theory that Mountbatten and the Queen Mum meddled in the affair, Sally Bedell Smith argues that Andrew's proposal was orchestrated by the Shand and the Parker Bowles families. The two dads apparently placing an engagement notice in The Times ahead of time, publicly forcing Andrew's hand.

It's possible there was royal pressure for them to get Camilla and Andrew safely married.

What happened next?

After Camilla married Andrew in 1973, they had two children: the food writer Tom Parker Bowles (who is actually Prince Charles's godson), and art curator Laura Lopes. The couple divorced in 1995, by which point they'd been living apart for two years. The reason for their separation was explained with the statement: "There is little of common interest between us."

Charles remained unmarried for some years – though there were some romantic entanglements, including a rumoured (rejected) marriage proposal to Mountbatten's favoured candidate Amanda Knatchbull. Other potential matches under Charles's consideration were Lady Jane Wellesley and Lady Sarah Spencer.

Then in 1981, he married Lady Diana Spencer after a speedy courtship and a brief engagement. He was now 32; she was just 20 years old.

Princess Diana soon gave birth to sons Prince William and Prince Harry, but it was not a happy marriage and they formally separated in 1992, divorcing in 1996.

The following year, Diana died in a shocking car crash in France.

When did Camilla and Charles get back together?

Charles had been heartbroken when Camilla married another man, writing to Mountbatten: "I suppose the feeling of emptiness will pass eventually." But he does not seem to have ever moved on from his first love.

It's hard to put an exact date on when Charles and Camilla rekindled their relationship. It's been suggested that they got back together soon after August 1979, when Charles's beloved great-uncle Lord Mountbatten was assassinated by the IRA – and the Prince turned to his married ex-girlfriend for solace; others have suggested that their romantic reunion occurred earlier, or later.

At this point Charles was still unmarried, while Andrew Parker Bowles reportedly had numerous lovers of his own and turned a blind eye (or even approved of) his wife's infidelity. But the affair with Camilla Parker Bowles continued even after Charles married Diana.

Charles and Diana's relationship was difficult from the start. Asked about being in love during their engagement in 1981, Diana replied "of course" – while Charles famously replied, "whatever 'in love' means." They were nicknamed "The Glums" and seemed unhappy in each other's company; by the late 80s the marriage had broken down entirely.

There were accusations of infidelity, a tell-all book from Diana, a televised interview with Charles, the "Camillagate" tape scandal, and finally the divorces of both couples. Then came Diana's death in 1997.

Camilla later moved in with Charles, but they did not officially marry until 2005. With Camilla a divorcée, they had a civil marriage at Windsor Guildhall (without either of Charles's parents present), followed by an Anglican blessing at St George's Chapel in Windsor Castle. Camilla was given the courtesy title of Duchess of Cornwall.