Photographs of Queen Elizabeth II from her earliest days on the throne in 1952 to 2015 will form part of an exhibition to celebrate her impending record reign as British monarch.
On September 9, the 89-year-old monarch is set to pass the record of 63 years, seven months and two days set by her great-great-grandmother Queen Victoria as the longest-reigning British head of state and the longest-reigning female monarch in history.
The new royal exhibition of formal photographs taken over the decades includes rarely seen images such as a black and white portrait by Dorothy Wilding painted in February 1952 soon after her accession to the throne, and Julian Calder's striking image of her on Scottish moorland as Queen of Scots.
Victoria ascended the throne aged 18 on June 20, 1837 and died on January 22, 1901.
According to the 'The Guardian', Buckingham Palace has calculated that Victoria reigned for 23,226 days, 16 hours and 23 minutes, taking into account 15 leap years, additional months and days.
Elizabeth became queen at 25 after the death of her father George VI, who died on February 6, 1952 while she was on an official visit to Kenya.
She became the longest-living British monarch in December 2007, overtaking Victoria, who was 81 when she died.
She is the second-longest serving current head of state in the world, after 87-year-old King Bhumibol Adulyadej of Thailand, who took to the throne in 1946 but is now rarely seen in public.
No official celebrations have been planned to mark the September 9 anniversary as the Queen will be in Scotland for her usual summer break at Balmoral Castle.
