Watch Ken Goodwin's report
From a young age the Queen was known for her love of horses, and developed an acute interest in horse racing throughout her reign.
Her mother was a regular visitor to Cheltenham races and the Queen herself attended much to the delight of staff, riders and trainers.
The Queen visited in 1953, the year of her coronation, and then 50 years later to unveil a statue to her late mother.
Edward Gillespie, Lord-Lieutenant of Gloucestershire, was first the Queen's and now King Charles' representative in the county. He was the managing director of Cheltenham Racecourse when the Queen visited.
He said: "I remember very well somebody shouting at her after the race 'Did you back the winner Ma'am?' and her turning to my chairman saying 'You know they don't shout at me at Royal Ascott'."
Ian Renton, who is now in charge of the racecourse says the late Queen's contribution to racing is immeasurable.
He said: "She has been invaluable in her contribution to racing over so many years.
"It is just unbelievable to have a monarch whose passion is horses and is racing [...] it has been wonderful to be a part of, and it to be of such interest to her late Majesty."
The Queen cherished her own horses too, and her knowledge and enthusiasm are regarded as irreplaceable at Cheltenham.
Edward Gillespie added: "These are home bred, she hasn't bought them at an auction, these have been her babies.
"She has nurtured them, she has probably seen them being born, she has nurtured them as young foals, she has seen them grow."