April 1940: Princess Elizabeth out riding at the Royal Lodge, Windsor. Photo / Getty Images
Queen Elizabeth "screamed" so loudly cheering on one of her racehorses that her security guards thought she was under attack, it has been revealed.
Nicky Henderson, one of the late monarch's trainers, recalled her telling him how the protection officers burst into her sitting room as her horse narrowly won a race.
It came as the racing world paid tribute to her unwavering passion for the sport.
Henderson, who trained many of her jumps horses, described her as "racing's patron saint" and "racing's best friend", saying: "I bet she would have loved to go racing every day, but her diary was a bit different to most people's."
Traditionally involved in flat racing, Queen Elizabeth inherited the Queen Mother's string of jumps horses upon her death in 2002.
Henderson said training a winner for her during the Platinum Jubilee celebrations this summer at Worcester had been a "huge thrill".
He described how excited she could get watching her runners.
"I remember once having a winner for her and she told me she'd been watching it in the sitting room. The horse led over the last, but it was a tight finish so she stood up and screamed it home.
"With that, she said the security guards burst open the door thinking there had been some ghastly drama, but found her shouting at the television rather than an intruder! That always tickled me."
It has also been revealed that the late monarch spoke to one of her racehorse trainers just two days before her death, with her passion for the sport undimmed until the very end.
Clive Cox, who trained the final winner of the monarch's career on Tuesday, described her as "sharp as a tack" during their telephone call.
It has emerged Queen Elizabeth found time to discuss the prospects of her filly, Love Affairs, just before accepting Boris Johnson's resignation and appointing Liz Truss the new Prime Minister at Balmoral.
The two-year-old won convincingly at Goodwood later that day, bringing to an end an owning and breeding career that saw her win some of the biggest prizes in the sport.
Cox, who trains several of her string, said: "Every time I have had a runner for Her Majesty I have spoken to her on the morning of the race.
"Those conversations have been the greatest privilege of my life but when I called on Tuesday I was told that the Queen was quite busy, which was understandable.
"But at 10 o'clock the phone rang and it was Her Majesty on the line."
Cox added: "We talked about the filly, how the race might pan out, how another horse of hers was doing in my stable, and about a couple of other things. She was sharp as a tack."
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