The Queen arrived at Royal Ascot for Ladies Day
The horse rider, in full uniform, was seen rolling on the ground as he tried to pick himself up.
The four carriages, led by the Queen, had just entered the winners’ enclosure when he lost his balance.
The Queen returned to Royal Ascot for Ladies Day alongside Princess Beatrice, Princess Eugenie and other members of her Royal Family.
The monarch arrived at the Berkshire racecourse along with the thousands of racegoers who have turned out for the glitz and glamour of the biggest day in the racing calendar.
She was joined by her son Prince Andrew, the Duke of York, Sir Nicholas Bacon and Sheikh Isa bin Salman Al Khalifa, in the carriage procession.
Princess Eugenie and Princess Beatrice sat in the second carriage with the Princess Royal and Vice Admiral Sir Tim Laurence.
In the third carriage is the Duke and Duchess of Gloucester and the Earl and Countess of Snowden, while Peter Troughton and his wife were in the fourth carriage with the Queen’s land agent Sir Marcus O’Lone and his wife Lady O’Lone.
The Queen then did a walkabout in the winners’ enclosure, shaking hands with owners and trainers.
The Queen wore a pink Stewart Parvin outfit and a hat by Rachel Trevor Morgan.
Princess Beatrice wore a dress by Jonathan Simkai, teamed with a Sally-Ann Provan hat.
Her sister Eugenie, who marries in October, chose royal favourite Erdem to design her outfit, along with a hat by Sally-Ann Provan.
It is the third time the Queen has attended the sporting event this week, after joining her granddaughter-in-law Meghan Markle for her race day debut on Tuesday.
A member of the Queen’s carriage procession falls
The member of the royal procession who fell did not appear to be injured
The 92-year-old has not missed a Royal Ascot week since she took to the throne in 1952.
And yesterday she took the royal box alongside her eldest son, Prince Charles and his wife Camilla, her cousin, Princess Alexandra and the Earl and Countess of Wessex, Prince Edward and his wife Sophie.
Hats of all shapes and sizes will be on display when Royal Ascot welcomes racegoers for Ladies Day.
The halfway point of the famous horse racing meet will see female racing fans making an extra effort with their headgear.
Princess Beatrice and Princess Eugenie at Royal Ascot for a second time this year
In past years nothing has been too outlandish or over the top for the event which encourages milliners to excel themselves.
Around 70,000 racegoers are expected to attend Royal Ascot and will be treated to the spectacle of the event’s premiere race the Gold Cup.
The Gold Cup began when the Royal Ascot was first formed. It is Ascot’s oldest traditional race.
Winners of the Gold Cup are given a golden trophy to keep.
The race takes place today at 4.20pm.
The Queen arrived at Ladies Day at Ascot with her son Prince Andrew
In 2013 the Queen became the first reigning monarch to own a thoroughbred, Estimate, which won the Gold Cup.
This year’s Royal Ascot began Tuesday, June 19, with races every day until Saturday, June 23.
Punters have already started placing bets on what colour hat the Queen will wear.
Bookies Coral make pink the 2-1 favourite, while green is second best in the firm’s betting at 3-1, and blue is 5-1.
Coral’s John Hill said: “It is ladies’ day at Royal Ascot therefore it is no surprise to see pink as the favourite in the betting on the colour of the Queen’s Hat.
“The majority of punters have got it right on both days so far this week and it will be a costly result if the Queen arrives in pink today.”
The Queen wore a pink Stewart Parvin outfit
Odds on the colour of the Queen’s hat today:
8-1 White or Cream