The most eye-catching arrivals at Royal Ascot 2018

Royal Ascot 2018 is well underway.

Five days of horse racing and flamboyant fashion kicked off on Monday with thousands of racegoers turning up in the Berkshire town in their finery. As always, the choice of headgear has, so far, been wonderfully experimental.

Take Kelly Brook, for example, who arrived on the first day of Ascot in a World Cup-inspired hat, complete with a miniature of former England football player Bobby Moore attached. Meanwhile, another brave fashionista opted for a hat fittingly adorned with a horse's head.

The annual event is also known for being a highlight in the Royal Family's calender, with the Queen attending Ascot every single day in numerous vibrant ensembles, and accompanied by various family members.

This year also marked the Duchess of Sussex's Ascot debut, which took place exactly a month after the royal wedding.

She certainly raised the style stakes on the opening day, arriving in a custom white dress by Givenchy—the same brand that designed her history-making wedding dress.

And as today is Ladies' Day, be prepared for even some bolder, even brighter, looks.

Scroll through the gallery above for all the sartorial highlights.