Cheering crowds and ecstatic racegoers have greeted the Queen as she made a grand entrance to Royal Ascot.
She rode in a carriage with the Prince of Wales and the Duchess of Cornwall at the head of a procession which travelled along the course past stands packed with punters.
The famous five-day meeting is as much a social event as an important sporting fixture and attracts some of the best thoroughbreds, jockeys and trainers in the world.
Among the famous faces at the Berkshire racecourse were opera singer Katherine Jenkins, Bollywood star Aishwarya Rai Bachchan and BBC sports presenter Gary Lineker.
Jenkins said she was attracted to the glamorous side of the event: "I love Royal Ascot, it's just so old-fashioned - old-fashioned glamour, old-fashioned traditions." The star wore a bright orange and pink hat by popular milliner Philip Treacy and a matching dress. She added: "I would wear a hat every day if I could."
The Queen is a passionate horse owner and breeder and, during her long association with Royal Ascot, has had 21 winners. Her horse Estimate will run in the Gold Cup on Thursday and is a favourite with some bookmakers.
A victory in the race would be a boost for the Queen, who will attend without the Duke of Edinburgh, who is convalescing at Windsor Castle after exploratory abdominal surgery.
The Queen waved to the racegoers as she went past and when the National Anthem was played Charles, who wore a morning suit, took off his top hat.
Royal Ascot is as much about the fashion as the racing and outlandish hats were out in force. But the Queen looked elegant in a peach cloque coat with matching floral silk dress and draped skirt by Stewart Parvin, and a hat by Rachel Trevor-Morgan. On her shoulder she wore a brooch, a gift from the Sultan of Oman, made of diamonds and representing English roses and foliage. Camilla wore a Bruce Oldfield white and gold coat, with a white dress and a matching hat by Philip Treacy.
When the carriages reached the racecourse's parade ring the royals stepped down and met some of the senior officials from Ascot. A minute's silence was observed for the horse trainer Sir Henry Cecil who died last week from cancer aged 70. He was one of the greatest flat trainers of the post-war era and trained one of the sport's best horses, Frankel. Sir Henry also had a strong association with Royal Ascot, training 75 winners over more than four decades. The royals stood in a semi-circle and observed the silence before taking their seats in their box for the first race.