As the Queen enjoys Saturday's Trooping the Colour celebrations for her official birthday, the BBC is releasing archive footage showing her taking the salute for the first time in 1951.
The footage forms part of a new online collection which collates key radio broadcasts, news items and footage chronicling the Queen's life as a princess between 1940-1952.
Her earliest BBC archive recording as a 14-year-old, newsreel footage of her wedding in 1947 and the announcement of the birth of Prince Charles are among 19 items which people will be able to access online.
BBC Archive executive producer Julie Rowbotham said: "This collection provides a fascinating insight into the contribution made by Princess Elizabeth through World War II and the post-war years leading up to her coronation.
"The BBC's remarkable archives enable audiences to learn much more about the time and also the important role played by the then princess in years that saw so much change."
In 1951, King George VI was unable to attend Trooping the Colour due to ill health, so his place was taken by the future queen.
She is seen riding side-saddle, wearing a modified version of the regiment's uniform. The young Prince Charles is riding alongside his grandmother, Queen Elizabeth, the future Queen Mother.
Viewers will also be able to see the Queen as she departs with her husband to Kenya in 1952, which was also the last time she saw her father, King George VI, alive. He would pass away later that year.
Meanwhile in 1940, the then Princess Elizabeth, 14, featured in a radio programme called Children's Hour.
The Queen pictured in 1947 before delivering a speech in South Africa
She is heard sending her best wishes to the children who have been evacuated from Britain to America, Canada and elsewhere. This is the earliest recording of the future Queen in the BBC archives.
In 1947, the archive includes a news report detailing the Queen's marriage to Prince Philip, then known as Lieutenant Philip Mountbatten.
As was customary at the time, newsreader Ronald Fletcher delivered the text of the court circular before offering best wishes to the happy couple on behalf of the listeners at home.
The collection features the wedding itself, with viewers able to see the couple leaving Westminster Abbey and their appearance on the balcony of Buckingham Palace.
Reports on visits by the Queen to Kenya and Athens, as well as her meeting with US president, Harry S Truman, are also included, as is a speech delivered by the Queen in Cape Town, South Africa, on her 21st birthday, can also be seen.
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