They drank. They swam. They smiled. But they didn’t hear the click of the cameras–or acknowledge that their secret romance could constitute a national scandal. They were Princess Margaret and Roddy Llewellyn, and they were about to grace the cover of a British tabloid with images that would end a marriage and change the face of British royalty forever.

Margaret’s marriage to Antony Armstrong-Jones, the First Earl of Snowdon, was already on the rocks, but it would take the photographs of her frolicking on a private island with another man to put the final nail in its coffin. In another era, the affair might have been private, too. But Margaret’s intense life was a tabloid editor’s dream, making her every move fodder for media scrutiny.

It happened on Mustique, a private island that is part of the Grenadines. In 1958, Colin Tennant, a British aristocrat who had once courted Princess Margaret, purchased and began developing it. The island had once been home to sugar plantations, all of which had been abandoned and overgrown since the 19th century. Under Tennant’s supervision, Mustique went from a scrubby, amenity-free island to a lush playground for the rich and famous. And when Margaret married Antony Armstrong-Jones, a free-spirited photographer, in 1960, Tennant gave her a plot of land as a wedding present.

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Over the years, Margaret’s wedding present turned into a retreat from the stresses of public life. At Les Jolies Eaux (The Beautiful Waters), an extravagant ten-acre villa, Margaret could relax and entertain her closest friends without worrying about public scrutiny.

But in 1976, Margaret’s private playground was punctured by a tabloid photographer. Back in England, blurry photos of Margaret and a man 17 years her junior created a gossip-fueled scandal.

The man was Roddy Llewellyn, a landscape gardener and aristocrat. The photos, which showed them in bathing suits, were taken as proof that Margaret had preyed on a much younger man.

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Photos of Princess Margaret and Roddy Llewellyn while on holiday on February 1, 1976 in Mustique, West Indies.

Margaret had met her lover through Tennant and his wife, Anne. After that first meeting, Anne Tennant told biographers later, her first thought was “Heavens, what have I done?” It was clear that Margaret—whose marriage with Armstrong-Jones had been on the rocks for years—was smitten. Soon, Llewellyn and Margaret were inseparable.

But though Margaret’s troubled love life had been news for decades, her open affair was still enough to shock and entertain tabloid readers. Straddling legitimate news and entertainment coverage, tabloid newspapers had become big business by the second half of the 20th century. And the British royal family was a beloved subject of the gossip rags. Margaret—troubled, beautiful and extravagant with her wealth—was a paparazzo’s dream, and the public was rabidly curious about her reportedly opulent life on Mustique.

That didn’t mean that they admired or protected the princess, though. When the photos surfaced, tabloid headlines skewered Margaret as a cradle robber who spent the public’s money partying. During this era, members of parliament even spoke out against her, calling her a “royal parasite” who wasted taxpayer funds and Llewellyn as her “toy boy,” a disposable lover who symbolized her rebellion against the strictures of royal life.

In reality, Margaret was deeply unhappy in her marriage, and her relationship with Llewellyn was a rare spot of solace. Lord Snowdon had conducted multiple extramarital affairs, and Margaret felt lonely within her marriage. Though her family had cheered on her relationship with a commoner, the reality of their marriage was different from what Margaret, who had grown up in a rarefied royal environment, expected. While she went through the usual round of official functions, Lord Snowdon worked full-time as a photographer for the Sunday Times, and was openly unfaithful to her. By the late 1970s, husband and wife were distant.

When the “compromising” images—tame by today’s standards—were made public in 1976, Lord Snowdon used them as an excuse to escape the strained marriage. He told Margaret’s personal secretary, Lord Napier, that he was leaving the princess. Napier, in turn, told Margaret, using coded language since he was speaking on an insecure phone line. “Oh, I see,” she reportedly replied. “Thank you, Nigel. I think that's the best news you've ever given me.”

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Princess Margaret with her husband Earl of Snowdon in the Bahamas on March 14, 1976. That month they announced their separation and their marriage officially ended two years later.

Margaret’s divorce was a scandal unto itself. Until her marriage dissolved, the royal family had looked down on divorce. Margaret herself had given up her relationship with Peter Townsend, a divorced war hero, because of the family’s taboo on marriage after divorce. She was the first senior member of the royal family to get a divorce in 77 years, challenging the world’s vision of what being a royal could mean.

READ MORE: Why the Royal Family Used to Forbid Marriage After Divorce

As for Llewellyn, he realized that he was playing a role in a much bigger drama. “I am not prepared to comment on the events of last week,” he said in a statement issued after the couple announced their separation. “I much regret any embarrassment caused to her Majesty the Queen and the royal family, for whom I wish to express the greatest respect, admiration and loyalty.”

But privately, Queen Elizabeth actually approved of Llewellyn and Margaret’s relationship. After Margaret’s death, she reportedly thanked Anne Tennant for introducing Margaret to her lover. In a 2018 documentary, Anne Tennant recalls that the queen approached her, saying “I’d just like to say, Anne, it was rather difficult at moments, but I thank you so much for introducing Princess Margaret to Roddy ‘cause he made her really happy.”

After the divorce, Lord Snowdon quickly married Lucy Lindsay-Hogg, with whom he had been conducting an extramarital relationship for years. Margaret and Llewellyn continued their relationship, withstanding public scorn and criticism for their affair. The tabloid kept pursuing the couple, and Llewellyn’s brother even sold photos of them together to pay off his debts.

Eventually, the affair fizzled, and Llewellyn married another woman. Beginning in the 1980s, Margaret began to suffer severe health problems exacerbated by her smoking habit. She died in 2002. Llewellyn, who had remained friendly with her through the end, attended her memorial service. But though Margaret had died, the tabloids’ obsession with her love life didn’t. Shortly after her death, the News of the World, the same publication that had published the photos of the couple in the 1970s, published an article supposedly written by Llewellyn about his love for the princess, which later turned out to be fake

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