The Queen's passion for Royal Ascot is well known, but rumours are rife the Duke and Duchess of Cambridge could make their first appearance at the famous sporting event.
Punters have been betting on the prospect of William and Kate joining the Queen in her carriage as the royal procession makes its way along the famous course.
William Hill bookmakers have even suspended the book on the Cambridges making an appearance at the racing meet, which begins on Tuesday.
Jon Ivan-Duke, a spokesman for the bookmakers, said: "We were offering odds of 2-1 that the Duchess would be in the Queen's carriage this week - this now looks a certainty.
"The question now is will Prince George be going too."
The firm is offering odds of 10-1 that William and Kate's toddler son will join them at the famous Berkshire racecourse.
The Royal Family - especially the colour of the Queen's hat - are usually the basis for novelty bets during the five-day racing event.
William Hill have made blue the 2-1 favourite for the colour of the Queen's hat on the opening day.
Mr Ivan-Duke added: "We have had our first gamble on the Queen's hat today with almost 85% of bets for blue. We think the gamble is based on the chilly weather forecast when blue would perhaps be more appropriate than yellow."
Known for its strict dress code in the Royal Enclosure, Royal Ascot is one of the highlights of the racing and social calendar.
Each year around 300,000 race-goers descend on the racecourse and drink their way through 51,000 bottles of champagne, eat 5,000 kilos of salmon, 2,900 lobsters, 7,000 punnets of berries and bet thousands on the horses.
The Queen is a passionate horse owner and breeder and has watched more than 20 of her thoroughbreds triumph at Royal Ascot.
Her thoroughbred Estimate won the Gold Cup in 2013, when the monarch could not contain her delight as it romped home.