The Goodwood Festival was looking distinctly un-glorious on its opening day yesterday.

Torrential rain threatened to turn the one of the premier events in the summer social calendar into a damp squib as crowds huddled under canvas marquees and bars when a light drizzle turned into one of the heaviest downpours of the summer.

But thousands of punters - whether paying members of the public, part of the fashion set or the numerous celebrities who are attracted every year - didn't let the weather dampen the garden party atmosphere as the Duke of Richmond launched the five-day meeting.

The Duke, who has been racecourse chairman for more than 30 years, wished visitors a prosperous day.

He said: "So far this season, we have seen some superb crowds and some very memorable racing at one of the world's most beautiful racecourses. May this continue for the next coming days."

The event is a chance for the racing set to let their hair down after the formality of Royal Ascot, and, as ever, the super-rich clasped flutes of Veuve Cliquot and mingled with those who had saved their wages for the coach fare to West Sussex and a burger for lunch.

Among the celebrities were fashion designer Bruce Oldfield and guitar legend Mike Rutherford of Genesis and then Mike and the Mechanics.

They were joined in the Duke's hospitality boxes by Des Lynam, a fervent Brighton and Hove Albion supporter.

Also seen mingling with racegoers on the lawn in front of the Richmond Enclosure was the Marchioness of Milford Haven, who is the social editor of Tatler magazine, and famous names from racing, such as Willy Carson, Frankie Dettori and tipster John McCririck.

Mr McCririck, dressed in his trademark striped jacked with carnation and puffing huge cigar, said: "This is one of the great meetings of the year and it's a great social occasion.

"Tell everyone reading this article in The Argus to come racing. They'll have a great time and they'll even see strange people like me hanging around."

Wendy Humphryes, 32, of Pulborough, said: "This is easily the best day out of the year. I'm not hugely into horse racing but I've been coming here for the last few years."

Justin Poulter, 23, of Peacehaven, said: "It might seem like an expensive way to get drunk, but it's one day you aren't going to forget."

Goodwood was put on the social calendar by King Edward VII, who described the meeting as "a garden party with some racing tacked on".

Set on top of the breathtaking Sussex Downs, Goodwood is internationally acclaimed as being one of the most beautiful racecourses in the world.

The world's most expensive thoroughbreds will be racing for record prize money of £1,863,000 million this week.

Some 120,000 people are expected over the five days - and there are 8,000 bottles of champagne on ice.