The queen granted the broadcaster unprecedented access to hundreds of home movies shot by her, her parents and her late husband Prince Philip, as part of celebrations for her upcoming Platinum Jubilee, honoring her 70 years on the throne.
The videos record the queen's life from when she was a baby in a pram to her coronation in 1953.
One clip captured the first extended visit of Philip to Balmoral Castle in Scotland in 1946, before his engagement to Elizabeth was made public. The footage depicts a beaming Princess Elizabeth showing off her engagement ring to the camera.
Philip and Elizabeth wed in November 1947 and were married for 73 years, until Philip's death last April just a few months before his 100th birthday.
Simon Young, the BBC's commissioning editor for history, said the broadcaster was honored to have access to the queen's personal film collection.
“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,” he said.
“Elizabeth: The Unseen Queen” will air in the U.K. on May 29, ahead of a week of national celebrations to mark the queen's 70 years on the throne.