Princess Margaret married Antony Armstrong-Jones, 1st Earl of Snowdon, on May 6, 1960, in a grand ceremony at Westminster Abbey. 

As the first royal wedding to be televised, it attracted a worldwide audience of 300 million. 

Meanwhile, around half a million spectators lined the streets, hoping to catch a glimpse of the princess as she travelled to the Abbey in a glass coach. 

Margaret dazzled onlookers in a simple ivory gown, featuring a demure V-neckline, cinched waist and full skirt made from three layers of organza. 

Although Norman Hartnell was responsible for crafting the dress, few realise that the design was imagined by her future husband, photographer Lord Snowdon.

In his book Elizabeth & Margaret, Andrew Morton reveals that Antony showcased his artistic flair by sketching the wedding dress before passing it to the couturier. 

The author emphasises that the gown's simplicity marked a departure from royal tradition, with no embroidery or embellishment. 

'The only glitter came from the Princess' magnificent, diamond Poltimore tiara,' he writes. 

Margaret and Antony first crossed paths in April 1956 when he worked as the photographer at the wedding of her friends, Lady Anne Coke and The Hon. Colin Tennant. 

However, they properly met two years later at a dinner party hosted by Lady Elizabeth Cavendish in 1958. 

Their engagement was announced on February 26, 1960, with Antony once again displaying his creativity by designing Margaret's engagement ring. 

The piece, inspired by her middle name, featured a ruby centre surrounded by a marguerite of diamonds to resemble a rose. 

Following royal tradition, Margaret's wedding ring was crafted from the same Welsh gold nugget used for Queen Elizabeth's ring. 

This nugget was later used for the rings of Princess Anne and Princess Diana. 

According to Mr Morton, playwright Noel Coward observed the Queen's demeanor during the wedding, noting that she 'scowled a good deal'. 

'While some might have interpreted that stern expression as a sign of ill-temper, those who knew her understood that she scowled when straining to control strong emotions,' the author claims. 

Labour politician Richard Crossman supported this observation, suggesting: 'Perhaps she was touched by the prospect that her mischievous, contrary little sister had finally found happiness - or so it seemed.'

The star-studded guest list of 2,000 included numerous celebrities, as well as Antony's housekeeper and the postman from his father's village in Wales. 

In contrast, Margaret 'did not welcome any of the Clarence House staff who had served her so loyally'. 

As she passed Lord Adam Gordon, the Comptroller of the Household, he bowed and said, 'Goodbye, Your Royal Highness.' The Queen Mother's page, Billy Tallon, overheard him add, 'And we hope forever.' 

'It summed up the frustration some of her staff felt about her often inconsiderate behaviour,' Mr Morton notes.

Despite this, Margaret had her moment in the spotlight, stepping onto the Buckingham Palace balcony to acknowledge the cheering crowds below. 

Following the wedding breakfast, she and Antony left in an open-topped Rolls-Royce as the Queen and other guests tossed rose petals at them, marking a role reversal from thirteen years earlier at Elizabeth's wedding. 

The newlyweds then travelled to Battle Bridge Pier in the Pool of London, where they boarded the royal yacht Britannia to begin their honeymoon.