The Duke and Duchess of Cambridge are joining the Queen at Royal Ascot today.
The Prince of Wales and Duchess of Cornwall are also attending the first day of the famous Berkshire meet, which attracts hundreds of thousands of punters.
Following the arrival of the Queen and royal party in the parade ring, the crowds are paying their respects to those who died in the Grenfell Tower fire and the London and Manchester terror attacks with a minute’s silence.
The Queen marked her official birthday on Saturday by issuing a statement acknowledging the “succession of terrible tragedies” and observed a minute’s silence before the Trooping the Colour ceremony began.
Johnny Weatherby, chairman of Ascot Racecourse, said: “We have all been deeply saddened by recent tragic events around the country.
“At the beginning of this important week for racing, we at Ascot Racecourse wish to pay our respects to the victims and offer support to the families who have been so terribly affected.”
The racecourse is making a donation of £100,000 to the British Red Cross UK Solidarity and London Fire Relief Funds and local charities to support those affected.
Exit collections on all five days of Royal Ascot will take place to enable racegoers to contribute.
The Queen has written a foreword to Tuesday’s official programme and highlighted the huge number of racegoers, and entered horses from across the globe, that make Royal Ascot such a “unique” event.
William and Kate will present a trophy during the day, as will Charles and Camilla, double Olympic gold medal-winning showjumper Nic Skelton and actor Laurence Fox, best known for his role in the TV crime drama Lewis.
The Queen said in her foreword: “The tremendous racing and the gathering of 300,000 people and more than 400 horses from around the world makes this event unique.
“Last year, horses trained outside Great Britain won 14 of the 30 races and I am again delighted to welcome many overseas competitors.
“In 1711, Queen Anne declared Ascot to be ‘ideal for horses to gallop at full stretch’. Ever since, the finest horses have raced here and that will certainly be the case again this week.”