The Queen will join thousands of horse racing fans today when she attends one of the nation's leading sporting events - Royal Ascot.
Some 300,000 spectators are expected over five days at the world-famous annual meet, where the Queen arrives each day in horse-drawn carriage.
Attracting some of the best thoroughbreds, jockeys and trainers in the world, it is also known for its display of flamboyant and exotic hats, with the most extravagant creations making an appearance on Ladies' Day on Thursday.
This year's high-profile international runners include Spielberg, one of the best middle-distance horses in Japan, and Able Friend from Hong Kong, while last year's Kentucky Derby winner California Chrome is hoping to overcome a foot injury to run.
Weather forecasters have predicted racegoers will enjoy glorious sunshine this afternoon, with temperatures reaching up to 22C.
A Met Office spokesman said the fine weather was set to continue throughout the week, with the mercury peaking at 23C tomorrow.
The Queen is a passionate horse owner and breeder and has had 22 winners during her long association with Royal Ascot.
Her thoroughbred Estimate won the Gold Cup in 2013, when the monarch could not contain her delight as it romped home.
But the horse was controversially stripped of its second-place finish last year after testing positive for morphine in July.
Bookmakers traditionally take bets on the colour of the Queen's hat, with pink named as favourite for today's curtain-raiser.
In the Royal Enclosure, a strict dress code must be observed.
Women must wear a hat or a "headpiece" which has a diameter of four inches or more.
Off-the-shoulder and halter neck dresses, dresses with a strap of less than one inch and fascinators are all banned.
Midriffs must be covered up and trouser suits should be full length and of matching material and colour.
Men must wear morning dress with a waistcoat and top hat.
According to organisers, last year’s racegoers enjoyed 51,000 bottles of champagne, 160,000 glasses of Pimms, 5,000 kilos of salmon and 2,900 lobsters.
Racing at Ascot dates from 1711 when Queen Anne drove from nearby Windsor Castle with her entourage for a day's sport organised at her command.
The Queen will unveil a new statue of five-times Ascot winner Frankel shortly after the opening race, the Queen Anne Stakes.
Frankel, who was trained by the late Sir Henry Cecil and is widely acknowledged as the greatest racehorse of the modern era, retired unbeaten following a 14-race career in October 2012.
The bronze statue, created by sculptor Mark Coreth, will overlook the parade ring, facing the winners' enclosure.