Derby Day has welcomed a regular face as the Queen arrived to watch the classic race and start her Diamond Jubilee celebrations in earnest.
The event is one of the highlights of the racing calendar and is rarely missed by the Queen who joined 130,000 enthusiastic racegoers for the great social occasion.
They gave the monarch and Duke of Edinburgh a huge cheer as they were driven down the course past the stands and hospitality tents.
Epsom racegoers celebrate the Jubilee on an open top bus ahead of the Queen's outing to the Derby
The royal couple were joined by a large party which included the Duke of York and his daughters Princess Beatrice and Princess Eugenie and the monarch's racing manager John Warren.
Unlike in last year's race, the Queen does not have a horse entered in the Derby, or the other six featured races.
The Earl and Countess and Wessex also joined the monarch in her royal box along with the Duke and Duchess of Gloucester, and Prince and Princess Michael of Kent.
Derby Day is a great social occasion when all elements of British society gather on the Epsom Downs.
While the wealthy wearing their morning suits and top hats sipped champagne in the Queen's stand, on the course's famous hill in the middle of the track a funfair and amusements were staged for ordinary punters.
Already a fun day out, the event had an added carnival atmosphere with stiltwalkers dressed as guardsmen complete with scarlet tunics and imitation bearskins amusing the racegoers.
Welsh singer Katherine Jenkins sang the national anthem as the Band of Her Majesty's Royal Marines Portsmouth played and when it ended, a huge cheer went up.
Many of the spectators waved Union flags and lined the Queen's route into the stand named in her honour and opened by the monarch in 1992.
Grey skies threatened rain but the Queen was dressed in a white silk dress with a blue floral print, and a royal blue crepe wool coat by Stewart Parvin and matching hat by Rachel Trevor Morgan.
The excitement built ahead of the Derby and the Queen was joined by her family in the parade ring as she got a closer look at the thoroughbreds due to race.
As they entered the grassed enclosure, Andrew, looking smart in a morning suit, stopped to avoid walking in front of a broadcast cameraman and then spotted former jockey Willie Carson, Epsom's guest of honour, and shook hands.
Beatrice and Eugenie, in figure-hugging summer dresses, found a group of people they knew and exchanged kisses, while Edward and Sophie were also seen chatting to others.
The Queen stood with Philip and her horse trainer, John Warren, who pointed out the thoroughbreds as they were led past.
When the Derby finally got under way, a great cheer went up and the bars, cafes and restaurants in the stands emptied as spectators flocked to the rails.
The Queen was not on the balcony with the rest of the royal party to watch as the favourite, Camelot, cruised from near the back of the field to a comfortable win.
But when it was paraded in the winner's circle, she came out into the bright sunshine to watch the jockey dismount and be congratulated by the owners and trainer Mr O'Brien, whose horse had earlier won the Diamond Jubilee Coronation Cup.
During the day a horse part-owned through a syndicate by the parents of the Duchess of Cambridge, Michael and Carole Middleton, ran in a race.
Sohraab, owned by Pangfield Racing, was entered in the Investec Specialist Bank "Dash" but finished well down the field.
The extended Bank Holiday weekend will also feature a majestic River Thames pageant on Sunday. The following day pop music legends will entertain the royals and Jubilee beacons will light up hilltops across the country.
On Friday prime minister David Cameron hailed the Queen saying she had never "put a foot wrong."
"She's hugely popular and respected here and around the world; it's an opportunity to give thanks and say thank you for the incredible service she has given."