"Princess Margaret said if there has to be a good princess, there has to be a bad one - that was her role in life, to be the bad one," satirist Craig Brown recalls of the royal in BBC two's documentary Princess Margaret: The Rebel Royal.
The two-part series focuses on Princess Margaret and Lord Snowdon's "colourful" personal lives, and the slow deterioration of their marriage - including the backlash against the royal family after the royal's scandalous affair with younger man Roddy Llewellyn.
The Crown's season 3 is also expected to explore this intriguing and highly-publicised chapter of Margaret's life, with Helena Bonham Carter taking over from Vanessa Kirby to play the party-loving princess. Ben Daniels plays Lord Snowdon.
The breakdown of Princess Margaret and Lord Snowdon's marriage
In 1967, Margaret had started seeing Scottish aristocrat and jazz pianist Robin Douglas Home, but after spending six weeks together, he was eventually banned from Kensington Palace. Life in the '60s reflected the social and sexual revolution that changed Britain during the 20th century - but it wasn't always women who benefited from this cultural shift.
By the early 1970s, Princess Margaret's marriage to photographer and filmmaker Lord Tony Snowdon began to irrevocably break down; Snowdon was described as a serial adulterer with a colourful sexual life, who encouraged Margaret to follow suit. Snowdon had embarked upon a new relationship with Lucy Hogg - who he went on to marry in 1978 - but all of this was to be overshadowed by Princess Margaret and Roddy Llewllyn's whirlwind romance.
Margaret and Roddy's affair begins
The pair were introduced by mutual friend Colin Tennant in '73; Margaret was 43 at the time, and Roddy, a British baronet, was 25. The press and members of Margaret's inner social circle were aghast by the age-gap.
Around this time, celebrity coverage was suddenly big business for magazines. There was also the ongoing pursuit by the European press for royal stories, and a new market opened up for payments for royal revelations and pap shots.
Margaret and Llewellyn were photographed while holidaying in Mustique, with the media fabricating a caricature of Margaret as predatory cougar, and Roddy as her hapless toyboy.
While Snowdon had behaved questionably during their marriage, it was Margaret's actions that were under immense scrutiny from the press and the public. Politicians harangued her behaviour, publicly condemning her as a "royal parasite" and a "floosie".
The way in which Margaret was judged and shamed for her relationship with a younger man was a precursor of how women and their sexual lives are criticised and pored over by the press today. The media intrusion resulted in Llewellyn releasing a curt statement to the press: "I very much regret any embarrassment caused to Her Majesty and the royal family.
"Could we please be permitted by the media who have besieged us to carry on with our work and private lives without interference."
Meanwhile, Margaret's public duties, the privilege of her Mustique getaways, and her reported income of £55,000 a year from the state were called into question by MPs and the media.
Llewellyn became swept up in his new celebrity status, transitioning from landscape gardener to pop star, and divulging details about Margaret during interviews with reporters. The Queen didn't approve, and there were concerns that Margaret's 'dalliance' with Llewellyn could damage public opinion about the monarchy.
By 1976, there was press speculation that Prime Minster Harold had resigned purely to divert attention from Princess Margaret's separation from Snowdon and her ongoing relationship with Llewellyn. Two years later in '78, Kensington Palace finally announced Margaret and Snowdon's divorce after 18 years of marriage.
Margaret set a precedence by becoming the first royal family member to divorce, paving the way for three of the Queen's children - Prince Charles, Princess Anne, and Prince Andrew - to be able to divorce years later.
Margaret and Llewellyn were still together, but he was banned from attending her 50th birthday in August 1980. Friends recall the royal asking them to give him dinner somewhere beforehand. Their relationship soon petered out, and in 1981, Llewellyn married Tatiana Soskin, daughter of the film producer Paul Soskin.
David Griffin, who was the royal's former chauffeur from 1977 to 2002, reveals in BBC Two's documentary The Rebel Royal that he and Princess Margaret destroyed all of her confidential correspondence with Llewellyn by setting all their letters alight in a dustbin after their break-up.
Princess Margaret and Llewellyn were together for eight years in total. Margaret never remarried.
BBC Two's Princess Margaret: The Rebel Royal is available to watch on iPlayer. The Crown season 3 returns to Netflix on Sunday, 17th November.
The cast of <i>The Crown</i> looks just like their real-life counterparts
