Following their wedding in 1960, the first ever Royal wedding to be televised, Princess Margaret and Antony Armstrong-Jones were known as one of Britain’s most glamorous couples.
But behind the scenes, their marriage was incredibly different.
But when Antony was commissioned to photograph Margaret, a secret relationship between the two began.
The Queen’s sister visited Antony in disguise at his studio and they were able to spend weekends together at a “safe house” of friends.
“Nobody knew about their relationship, there wasn’t a whisper about it,” royal biographer Anna de Courcy told Town and Country Magazine.
“She would see him in secret at his studio and yes, he would join her at parties, but no one could pinpoint which man she was interested in,” she explained.
But while the pair were described as being "besotted" with each other, Antony continued to conduct multiple affairs right up until their engagement.
Not only was the photographer involved with actress Gina Ward and actress Jacqui Chan, he also fathered an illegitimate child with his close friend, Camilla Fry.
Polly Fry, who was born just weeks after Antony wed Princess Margaret, completed a paternity test in 2004 which confirmed Antony was the father.
Despite Antony's countless affairs, the pair became engaged on February 26, 1960.
Although the Queen happily gave her approval for the engagement, she requested they delay the official public announcement until after the birth of her son Prince Andrew.
Their wedding, which followed on May 6 1960, was attended by Antony's two ex-wives as well as his former lover, Jacqui Chan.
The tradition-breaking marriage saw Antony become the first commoner to marry into the British Royal family in over four centuries.