The Queen was joined by her children and grandchildren for a day out at Royal Ascot races.
Thousands of racegoers braved the rain and were treated to the sight of senior royals making their way along the famous Berkshire course to mark the start of the event.
Former England rugby star Mike Tindall, husband of the Queen's granddaughter Zara Tindall, pulled out a tiny top hat to amuse the Queen and other royal to mark the celebratory event.
The Queen was joined in her carriage by the Duke of York and King Willem-Alexander of the Netherlands and his wife Queen Maxima, who on Monday attended an Order of the Garter service at Windsor Castle.
Prince William and Kate followed closely behind, alongside the Prince of Wales and Duchess of Cornwall.
The Princess Royal and the Early and Countess of Wessex were in a third carriage, while the final coach carried Princesses Beatrice and Eugenie.
Only Prince Harry and Meghan were absent, with the couple looking after their six-week-old baby Archie.
In the official programme, the Queen wrote about her passion for race horses and her love for the annual event in Berkshire.
She wrote: "Racing began at Ascot over 300 years ago and while much has changed, the horses remain the stars, thrilling us with their beauty, brilliance and courage.
“The quality and depth of competition at the royal meeting has also continued to prosper, with eight group one races taking place this week.”
The event is regularly attended by the Queen, who is a keen horse owner and passionate breeder of thoroughbreds with more than 20 Royal Ascot winners.
Royal Ascot is as much a social and fashion occasion as a sporting event, and racegoers took the opportunity to turn on the style, from chic hats and summer dresses to sharp suits and top hat and tails.
The royal men looked smart in their morning suits and silk top hats, while the Queen was elegant in an Angela Kelly outfit and hat, with a Canadian Northern Star diamond brooch.
Kate wore an Elie Saab outfit with a hat by Philip Treacy, while Sophie looked stylish in an Emilia Wickstead dress and Jane Taylor hat.