Cheering crowds and ecstatic racegoers 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 on Tuesday were opera singer Katherine Jenkins, Bollywood star Aishwarya Rai Bachchan and BBC sports presenter Gary Lineker.
The inquest opens today into the death of an exiled Russian oligarch found dead at his home in Ascot.
Boris Berezovsky was found in his bathroom last Saturday.
A post mortem examination carried out earlier this week found that his death was consistent with hanging.
Racegoers at Royal Ascot Ladies Day are likely to need their umbrellas as today's rain threatens to put a dampener on the event.
The Met Office has issued a yellow weather warning for London and the south east as the longest day of the year gets off to a wet start.
A thunderstorm is forecast for 2pm, when the Queen is due to travel to the racecourse in a horse-drawn carriage.