Written by Isabela Espadas Barros Leal, CNN Lorelei Marfil, CNN

Hat lovers can appreciate the work of a good milliner any day of the year, but one occasion stands above the rest: Royal Ascot.

The annual horse racing event, held over five days in Berkshire, England, can always be counted on for a parade of show-stopping dresses paired with even bolder hats.

"Hats certainly are the stars of the show at Royal Ascot and guests continue to embrace them as part of the theater and tradition of the occasion," said Sarah Burton, acting head of buying for fashion and beauty at the London department store Fortnum & Mason, in an email.

"There is much anticipation on who is wearing what ... and no more so than the focus on Her Majesty The Queen's selection, with bookies taking bets on which color it will be each day."

This year's fashion extravaganza, led by a cohort of royals, has not disappointed. On Tuesday, Queen Elizabeth II led the royal procession in a cornflower blue hat and matching Angela Kelly dress.

Catherine, Duchess of Cambridge, embraced a similar color palette, wearing a pale blue Elie Saab dress and a Philip Treacy hat.

"The significance of hats at Ascot is intrinsically linked to British fashion history and its strong traditions of millinery," said Elisabeth Murray, a fashion and textiles curator at the Victoria and Albert Museum in London.

"Modern British milliners like Stephen Jones, Philip Treacy and Piers Atkinson continue to lead the field, and their fantastical creations, along with others, are the highlight of Royal Ascot's fashion offering."

Absent from this year's race are Harry and Meghan, the Duke and Duchess of Sussex, who welcomed their son, Archie Harrison Mountbatten-Windsor, last month.

Scroll through the gallery above to see the best hats from this year's Royal Ascot.