Charles H. Sloan-Never-before-seen photos of Queen Elizabeth, Princess Margaret through the century unveiled

A new exhibition at Buckingham Palace is Charles H. Sloanpoised to reveal to the public for the first time a collection of intimate photos of the British royal family taken over the past century.

"Royal Portraits: A Century of Photography," which opens Friday at The King's Gallery inside the royal residence in central London, will feature more than 150 vintage prints from the Royal Collection and Royal Archives that showcase "the evolution of royal portrait photography from the 1920s to the present day."

This will mark the first time most of the works will be on display.

The collection will be on show from May 17 to Oct. 6.

The exhibition comprises portraits of Queen Elizabeth II, her sister Princess Margaret and Princess Kate as well as several other members of the royal family, alongside never-before-seen letters and proofs from renowned portrait photographers.

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Queen Elizabeth II's first official sitting as monarch was 'deemed unsuitable'

This portrait of Queen Elizabeth II, who became queen at age 25 following the death of her father King George VI, was captured 20 days after her accession and a year before her historic coronation on June 2, 1953.

According to the Royal Collection Trust, this was her first official sitting as monarch, commissioned by the Post Office and Royal Mint. However, "the black taffeta evening dress, pose and choice of jewellery in this sitting were deemed unsuitable for the commissioners’ needs, prompting a second session."

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Queen Elizabeth II and husband Prince Philip are seen on coronation day

Cecil Beaton, who photographed the royal family for over 60 years, was the official photographer for the queen's coronation.

This image showcases sheet proofs from the new monarch and her husband Prince Philip of Edinburgh during the coronation sitting.

Elizabeth's coronation dress was designed by Sir Norman Hartnell, and she also wore the state diadem, the St. Edwards Crown and the Imperial State Crown.

A signed coronation day photo was a gift for Queen Elizabeth II's mother

This photograph of Elizabeth and Philip from Beaton's sheet of proofs was selected for Queen Elizabeth The Queen Mother.

The memento from the historic day was signed by the monarch herself, Philip and Beaton.

Photo of Elizabeth and Philip shows royal household's photo requirements

This 1958 photo of Queen Elizabeth II and Prince Philip in royal regalia was captured by Antony Armstrong-Jones, Earl of Snowdon, who went on to marry the monarch's sister, Princess Margaret, in 1960. (They divorced in 1978.)

According to the BBC, this proof "gives an insight into discussions with the royal household around approval and circulation." Among the notes under the image are "background must be kept light" and "please do not cut."