It was one of the late Queen's favourite events where she often looked her happiest.
Today Royal Ascot returns for the first time since Elizabeth II's passing last year - with King Charles and Queen Camilla set to lead the royals in the carriage procession.
Not only did punters at the racecourse and watching at home stake money on the horse racing, but another popular and fun bet also concerned Her Majesty.
It would see people having a flutter trying to guess what colour hat the late monarch would be wearing thanks to her love of bright colours.
Many Ascot fans had wondered if the betting on the colours of royal hats would still go ahead this year - and it appears it most certainly will.
Bookmaker Ladbrokes said it will be offering odds for punters wanting to guess the colour of Camilla's hat - although it is unknown whether it will remain a popular flutter.
Nicola McGeady, Head of PR at Ladbrokes told the Mirror: "Punters have long gambled on the colour of the Queen's hat.
"It is a traditional, fun flutter that has been a part of Royal Ascot for a very long time.
"With the torch being passed to Queen Camilla, we will keep offering odds on what colour she wears on all five days. Whether it remains as popular a bet remains to be seen."
So what colour is Ladbrokes tipping to be the favourite on the first day of the race meeting today?
Nicola added: "Her late Majesty was daring in the fashion stakes, wearing bold and bright colours, but we think Queen Camilla may go for a more muted approach with cream and white shades the favourite.
"She does veer towards blues and navy a lot also so that has been chalked up as the second favourite. However, she may surprise us with bolder colours as the week goes on."
Fellow bookmaker Coral is also offering odds on the colour of the Queen's hat as is Star Sports, which is also offering odds on the colour of Camilla's hat as well as the colour of King Charles' tie.
The late Queen used to attend every day of Royal Ascot - although it is unknown if Charles and Camilla will be at all five days of the race meeting this year. However, there is usually a whole range of royals attend every day - with the Prince and Princess of Wales often enjoying a day there at least once.
Meanwhile, it has been revealed that Royal Ascot has renamed one of its biggest races in honour of the former monarch.
The feature sprint, the Platinum Jubilee Stakes which is staged on the Saturday of the five-day meeting, will now be known as the Queen Elizabeth II Jubilee Stakes.
