Photos from the Royal Ascot show how attendees went all out for the return of the UK's most prestigious racing event

Attendees dressing up for Royal Ascot 2021 (Left) Prince Charles, Prince of Wales attends Royal Ascot (Right).Samir Hussein/ Getty Images

• Brits and royals are dressing up for the Royal Ascot, the UK's most prestigious horse race.
• The Royal Ascot, which takes place at Ascot Racecourse in Berkshire, opened Tuesday and ends Sunday.
• Prince Charles and Camilla, Duchess of Cornwall, as well as Princess Anne, are among the 12,000 guests.

Tuesday marked the opening day of the Royal Ascot, the UK's most prestigious five-day horse racing event that was founded by Queen Anne in 1711.

William Buick on board Kemari on their way to winning the Queen's Vase on Day Two of the Royal Ascot Meeting at Ascot Racecourse.      Harry Trump/Getty Images

Source: Royal Ascot

The event takes place at Ascot's Racecourse, a town in East Berkshire, which is about an hour's drive west of London.

A map showing the location of Ascot Racecourse, a town in East Berkshire, England, 25 miles west of London.      Google Maps

The races typically combine sport, fashion, and betting with day-drinking and socializing, attracting spectators from across the UK.

Racegoers attend Royal Ascot 2021 at Ascot Racecourse.      Samir Hussein/WireImage

It is the first Ascot since 2019, as the 2020 races were held privately as a result of the pandemic.

Kemari and William Buck coming home to win the Queen's Vase during day two of Royal Ascot at Ascot Racecourse.      David Davies/PA Images via Getty Images

Source: Royal Ascot

This year's Royal Ascot plans to see 12,000 guests in attendance each day. It's one of the UK government's pilot sporting events to take place before all COVID-19 restrictions are expected to be lifted on July 19.

Racegoers pose for a photo on Day Two of the Royal Ascot Meeting at Ascot Racecourse.      Harry Trump/Getty Images

Source: Royal Ascot, Gov.UK

At the races, attendees often get creative and eccentric with their hat and outfit choices.

Racegoers attend Royal Ascot 2021 at Ascot Racecourse.      Samir Hussein/WireImage

For the return of the famed equestrian event, people didn't hold back this year. Brightly colored, ornate hats filled the racecourse.

Yulia Shirokova wears an ornate hat on the second day of the Royal Ascot.      Alastair Grant/AP

Royal family members attended the race, including the Queen's daughter, Princess Anne. The Queen - who traditionally opens the horse races - was absent on its opening day this year, according to Vanity Fair.

Princess Anne, Princess Royal attends Royal Ascot 2021 at Ascot Racecourse.      Chris Jackson/Getty Images)

Source: Vanity Fair

Camilla, Duchess of Cornwall, and Prince Charles attended the races following dress codes of their section, the Royal Enclosure. Men are supposed to wear a full morning suit with a waistcoat and a top hat. Women must wear modest dresses and hats with a minimum diameter of four inches.

Camilla, Duchess of Cornwall and Prince Charles, Prince of Wales attend Royal Ascot 2021.      Samir Hussein/WireImage

Source: Royal Ascot

Beyond the Royal Enclosure, each section has a unique set of dress codes. The Windsor Enclosure is the most relaxed, with no dress code at all.

Francesca Cumani and Charlotte Hawkins attend Royal Ascot 2021.      Chris Jackson/Getty Images

Source: Royal Ascot

In addition to getting to sport their finest attire and revel in the lively atmosphere, spectators can try their luck by betting on the horses. The Royal Ascot has seven consecutive races that begin at 2:30 p.m. every day.

Kemari ridden by jockey William Buick (front, center) on their way to winning the Queen's Vase during day two of Royal Ascot at Ascot Racecourse.      by Steven Paston/PA Images via Getty Images

Source: Royal Ascot