In pictures: Royal Ascot Ladies' Day

Ladies Day, on the third day of Royal Ascot, is a major fixture of the social season, and traditionally the busiest day of the five-day meet.

The dress code is strict. In the Royal enclosure a hat must be worn, strapless dresses are banned, midriffs must be covered, and trouser suits, of full length, must match.

But despite the rules, there is plenty of room for creative sartorial expression.

In the Royal Enclosure, headpieces with a base of less than 4in (10cm) in diameter are deemed "unacceptable" - but there is no upper size limit

"Art couture" designer Larisa Katz topped her striking red outfit off with one of the larger headpieces of the day

Others opted for more muted elegance

There was a trend for wildlife-inspired headwear among many racegoers

This trio stepped out in an explosion of tropical foliage

An outfit designed by Inga Kovalerova took the botanical theme further still

The Queen's hat caused some problems for bookmakers. Its official colour - "pistachio" - was not on their betting list. They decided to pay out on four colours: white, blue, green and turquoise.

Model Lystra Adams sported feathers in the colours of the Jamaican flag with green lipstick to match

A number of other racegoers also made a statement with feathers and flowers

The Tootsie Rollers singing group showed off their matching white 1950s themed outfits

While this group of friends went for a kaleidoscope of contrasting colours

Princesses Eugenie and Beatrice looked demure as they watched the racing from the Royal enclosure

Outside the grounds, anti-horse racing activists Polish pop star Pola Pospieszalska and model Victoria Eisermann drew attention with more risque choices of outfit

This group took a break from the racing and made the most of the sunshine with a picnic in the carpark

Meanwhile, others carried their lunch on their head. Yaseen Ali-Choudhrey wore a hat made of sausages

Racegoer Jennifer Dardling sported a teddybear's picnic-inspired headpiece

And Ladies' Day wasn't just about the women - there was room for some creative get up from the men too

Which became more creative as the day progressed

Even the canine contingent made an effort with the dress code

Headwear remained intact, but by the end of the day there were a few tired legs