Hat's off! The Queen and the Duke of Edinburgh arrive for the first day of Ascot
Sister act: Beatrice and Eugenie look demure as they arrive at the event in Berkshire
Beatrice wore a black and nude dress while Eugenie opted for lace dress by Issa and a cream jacket
The princesses looked elegant in smart attire and wore a more toned-down look than at the Royal Wedding.
Eugenie, 21, wore a teal lace dress by Issa, matching hat and white jacket.
Beatice, 22, looked demure in a nude and black outfit.
Prince Charles and Camilla were also at the event, but there was no sign of the Duke and Duchess of Cambridge.
Royal enclosure: The Queen and Sophie of Wessex
Prince Charles and the Duchess of Cornwall accompanied Beatrice and Eugenie in the same carriage
Look familiar? Camilla wore the same outfit as she wore to the Royal Wedding in April
Camilla followed in the footsteps of Catherine, who has been pictured in a number of recycled outfits lately, wearing the same blue coat and dress she wore to the Royal Wedding.
Also in attendance was Danielle Lineker, who did her best Posh impression, posing in a nude Victoria Beckham dress.
The model teamed the v-neck frock with an on-trend floppy Rachel Trevor-Morgan hat and Christian Louboutin high heels.
Accompanied by her husband Gary, the couple cut a fine figure on day one of the races.
Also in attendance is Jackie St Claire, a regular at the five-day meeting at the famous Berkshire racecourse, that is set to attract royals, celebrities and horse-racing fans alike. Jackie wore an elegant grey dress offset by a larger-than-life yellow hat.
Holly Valance wore a beautiful black dress with an equally beautiful black lace beret, stunning.
A statue of Ascot equine legend Yeats is to be unveiled during the Royal meeting, which runs until Saturday. The four-time Gold Cup winner dominated Royal Ascot from 2006 to 2009.
Theatrics: A punter gets creative left, and Anneka Tanaka-Svenska models a Louis Mariette head-piece, right
An extra group race, the Tercentenary Stakes, has also been introduced this year to mark the anniversary.
Ascot's chief executive Charles Barnett said: 'This year is a true milestone at Ascot as we mark 300 years of tremendous sport and colourful history at the Royal racecourse.'
Gold Cup day on Thursday - known as Ladies' Day - will be one of the most popular days of the meet, with extravagant outfits and hats on display for the annual festival of fashion.
Fashion parade: Rules state that midriffs must be covered up
Celebration: This year's Royal Ascot is taking place as the venue celebrates its 300th year, having been founded by Queen Anne in 1711
They call me mellow, yellow: A pair of punters get festive
Those in the Royal Enclosure will have to adhere to the strict dress code however.
Women must wear a hat or 'substantial fascinator' with off the shoulder and halter neck dresses, dresses with a strap of less than one inch and miniskirts 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.
Fascinating: Ladies in high fashion check the form
Dress code: Women in the Royal Enclosure must wear a hat or 'substantial fascinator'
Danish-born designer Isabell Kristensen wears one of her own designs
A close eye will also be kept on what the Queen is wearing, with hundreds of bets placed on the colour of her hat for Gold Cup Day.
Nearly 500 horses are due to run in 30 races this year. Attendance at last year's Royal Ascot was 284,201.
Each year, the crowds consume some 170,000 bottles of champagne, around 10,000 lobsters, 5,000 oysters and 18,000 punnets of strawberries.
Culture shock: Three Japanese racegoers arrive in traditional Japanese dress
Say cheese! Ladies pose as a friend captures them on camera
