In pictures: Royal Ascot day one

Royal Ascot galloped out of the starting gate on Tuesday, with an estimated 290,000 people expected to attend this year.

The five-day event at Ascot Racecourse in Berkshire is a showcase for a fabulous array of world class horses and, of course, hats.

The enclosures at Royal Ascot uphold their own distinguished dress codes, resulting in a colourful variety of outfits on day one.