The true story behind The Crown's tangled love square between Prince Charles, Princess Anne and the Parker-Bowles.

If you’ve been watching The Crown, then you’ve probably found yourself obsessively intrigued in the bizarre relationship between Prince Charles, Princess Anne, and Camilla and Andrew Parker Bowles.

Prince Charles and Camilla’s scandalous affair made headlines around the world, but you’d be forgiven for not knowing about Princess Anne’s romantic fling with Andrew Parker Bowles.

You see, when Camilla met Charles she had already been dating her now ex-husband Andrew on and off for about five years. But Andrew had also dated Charles’s younger sister, Anne.

Yep, it’s not so much a love triangle but more of a strange love... square.

Watch the trailer for The Crown season four below. Post continues after video.

The entangled relationship features in the third episode of The Crown season three, but there were some elements historic drama got wrong.

Here’s a look at the true story behind the royal love affair.

Princess Anne and Andrew got together long before Charles and Camilla were ever a thing.

In The Crown, we see Andrew pursue Anne during a break from his on-again-and-off again relationship with Camilla. Meanwhile, Camilla is being distracted by a starry-eyed Prince Charles. It made for a juicy storyline, but in actual fact, the two relationships never overlapped in real life.

Royal biographer, Sally Bedell Smith told Vanity Fair, Charles did not meet Camilla until "the summer of 1972—long after Andrew and Anne’s romance was over. They were introduced by mutual friend Lucia Santa Cruz, who told me about inviting them over for a drink at her flat in London."

Anne and Andrew started dating two years before that in June 1970, after they met at the Royal Ascot racecourse and bonded over their shared love of horse racing.

Alas, their relationship was never meant to be. Just as we saw in the show, they had a short-lived romance. "Anne and Andrew enjoyed each other’s company, but they could never marry because he was a Catholic," Smith told the publication.

Despite their fling, Anne and Andrew still remain close friends to this day. Anne even named Andrew the godfather of her youngest child, Zara, who she shares with her ex-husband Captain Mark Phillips.

There were also rumours going around that Andrew and Anne continued to have a relationship even after they were married to different people.

Prince Charles fell very much in love with Camilla but she was still hung up on Andrew.

When Charles met Camilla through their mutual friend Lucia, he fell head over heels.

According to Penny Junor, author of The Duchess: The Untold Story, "[Charles] loved the fact that she smiled with her eyes as well as her mouth, and laughed at the same silly things as he did. He also liked that she was so natural and easy and friendly, not in any way overawed by him, not fawning or sycophantic. In short, he was very taken with her, and after that first meeting he began ringing her up.”

Camilla was interested, but she didn't feel as strongly for Charles.

"Charles fell madly in love with Camilla, but to her it was a fling—he was the Prince of Wales. Meanwhile, Andrew was off in Ireland and Cyprus for six months."

The pair later called things off when Charles joined the Royal Navy in 1971.

The royal family had nothing to do with Andrew and Camilla's engagement, but their parents did.

The royal family's secret plot to break up Charles and Camilla was another one of the show's scandalous storylines.

But in reality, "interfering like that is something the queen would never do," says Smith.

"It was highly unlikely that she [the Queen] even knew about Charles and Camilla... They were sort of under the radar. The only one who really knew about it was [Charles’s great-uncle] Lord Mountbatten, and he promoted it. He invited them to Broadlands together. But the idea that the queen and the queen mother would conspire like that is laughable."

And if anyone was doing the plotting, it was actually Camilla’s and Andrew’s fathers, Bruce Shand and Derek Parker Bowles.

Their fathers "were tired of Andrew’s foot-dragging" so they got together and published an engagement announcement in the Times in 1973.

"Once that happened Andrew was forced into proposing. But it wasn’t because of anyone in the royal family."

The couple ended up getting married that summer at the Guards Chapel in London, and oddly enough Princess Anne attended the ceremony.

But Prince Charles didn't take the news as well as his sister and was reportedly devastated. "I suppose this feeling of emptiness will pass eventually," he wrote in a letter to Lord Mountbatten.

Camilla and Andrew went on to have two children together but divorced in 1995 because Charles and Camilla were back together having an affair.

Charles ended up divorcing Princess Diana a year later. And after a very complicated love story, the pair ended up marrying in 2005. The rest, as they say, is history.

Feature Image: Getty.