Rare, private home movies of the Queen, filmed by members of the royal family, will be broadcast for the first time ahead of the Platinum Jubilee.
Her Majesty will be seen showing off her engagement ring during Prince Philip's first extended stay at Balmoral in 1946, before their engagement had been publicly announced, and as a young mother to Prince Charles and Princess Anne, along with her own parents the King and Queen as doting grandparents.
WATCH: Get all the details about the Queen's Platinum Jubilee
The BBC's 75-minute film, Elizabeth: The Unseen Queen, shows the baby princess being pushed in a pram by her mother, the then Duchess of York, and reveals behind-the-scenes footage from her first ever trip abroad, a tour of South Africa with her parents King George VI and Queen Elizabeth and her sister Princess Margaret.
Princess Margaret and Princess Elizabeth with their beloved father King George VI onboard HMS Vanguard in 1947
Filmmakers searched through 400 reels of film, which have been held privately by the Royal Collection Trust in the vaults of the British Film Institute.
The unique documentary shows the Queen as a child, a young girl and a mother in the lead up to her Coronation and tells the story of her life in her own words, drawn from some 300 of her speeches.
A 20-year-old Princess Elizabeth enjoying a visit to South Africa in 1947
Other rare moments include her grandfather George V, known to The Queen as "Grandpa England", sailing with The Queen Mother off the Isle of Wight in 1931, and footage of Princess Elizabeth with her uncle Prince George, The Duke of Kent, who tragically died in a plane crash in 1942 while on active service - and a poignant glimpse of the Royal Family at Balmoral in 1951, The King’s last visit there.
A beaming Princess Elizabeth shows off her new engagement ring soon after Prince Philip’s marriage proposal at Balmoral in 1946
Simon Young, the BBC's Commissioning Editor for History says: "This documentary is an extraordinary glimpse into a deeply personal side of the Royal Family that is rarely seen, and it's wonderful to be able to share it with the nation as we mark her Platinum Jubilee."
The programme will air on Sunday May 29 on BBC One and BBC iPlayer.