Queen Elizabeth II
Queen Elizabeth II's 21st birthday speech was recorded while she was in Zimbabwe. Pictured: The Queen arrives for the state banquet in her honour at Schloss Bellevue palace on the second of the royal couple's four-day visit to Germany on June 24, 2015 in Berlin, Germany. Getty Images/Sean Gallup

Queen Elizabeth II’s 21st birthday speech that moved thousands of people to tears reportedly had a huge secret.

Robert Hardman, the author of the new book “Queen of the World,” said that people were thought to believe that the Queen gave her speech live while she was in Cape Town, but she wasn’t really there. The Queen also did not give the speech live.

A diary by the King’s press secretary, Captain Lewis Ritchie, revealed that on April 13, 1947, in Zimbabwe, the Queen recorded her speech for the BBC.

“At 6 p.m., Princess Elizabeth recorded her speech for the BBC. It was afterward played off for Her Royal Highness to hear and was a great triumph,” it read (via Express).

The archived diary entry confirmed that the Queen’s speech was pre-recorded and was broadcasted a week later.

“None of which makes a lot of difference either to the content or relevance of this great speech. However, it has always been a source of enormous pride to South Africans – and a key part of the modern Commonwealth narrative – that the future Queen made her selfless act of dedication to South Africa. It would now seem that Zimbabwe can stake a claim, too,” Hardman said.

In related news, Hardman’s book will honor the Queen’s legacy over the years. It will also chronicle her travels across the world. The book is also tied up to ITV’s documentary, “Queen of the World,” which will feature glimpses into Her Majesty’s life, family, and royal collection over the past couple of decades.

Never before seen footage of the Queen’s life, which includes her 1954 Commonwealth tour, will also be included in the documentary. The Queen’s only daughter, Princess Anne, recalled the time she embarked on the six-month tour.

“I have very good memories of that trip – the journey out and the sea nannies that we had to stop us from launching ourselves over the side! We were kept very busy. There was lots to do, all sorts of places to go and things to keep clean – lots of scrubbing and polishing; that was part of our role,” she said.