As Royal Ascot moves north for the first time in its history, Peter Archer takes a look at the customs behind this highlight of the English social scene

The Queen is on unfamiliar turf this week as Royal Ascot is held at York racecourse. It is the first time in the royal race meeting's long history that it has taken place anywhere else but Ascot, a short gallop from Windsor Castle.

But redevelopment of the Berkshire course, which is owned by the Crown, has meant Royal Ascot is this year a Northern affair. And it seems that some regular racegoers are less than enthusiastic about making the trip to York.

For those who prefer the south, there is even a fake Royal Ascot beamed live from York where punters can parade in their finery, sip Pimms, place bets and pretend nothing has changed.

A highlight in the royal calendar and social season, the annual race meeting is a great British sporting occasion. It mixes top horseracing with extravagant hats, champagne, smoked salmon, strawberries and cream, and the unreliable English summer.

The Queen and the Duke of Edinburgh usually attend every day of the week-long meeting which begins each afternoon with a royal carriage procession.

The Prince of Wales, the Duke of York, the Princess Royal and her daughter Zara Phillips - the only Royal to have her own personal stylist - the Earl and Countess of Wessex, as well as the Duke and Duchess of Gloucester, and Prince and Princess Michael of Kent, are all regular Ascot racegoers.

Ladies Day, tomorrow, is a favourite opportunity for stylish fashion statements and hats, of course, are as much the focus as horseflesh. The Queen often wears a distinctive colour and she chooses a narrow brim so as not to mask her face. Also, a wide-brimmed hat is more likely to be whipped off by high winds.

Royal Ascot dates from 1711 when Queen Anne drove from Windsor with her entourage for a day's sport organised at her command. The present Queen first went to Ascot in 1945 and has attended every year since.

The Queen used to give a large house party at Windsor Castle for each meeting and until 1963 names of those attending were listed in the Court Circular. This year, the Queen and Prince Philip are staying privately near York.

Ladies attending the Royal Enclosure are required to wear formal day dress with hats covering the crown of the head, and gentlemen morning dress or uniform. A relaxation of the rules was allowed in 1968 when men could wear lounge suits. However, few actually did and the following year the rules reverted to formal dress.

Ladies have been allowed to wear trouser suits since 1970 but hats are still obligatory. Overseas visitors are welcome to wear the traditional national dress of their country.

The Royal Enclosure dress code is policed by stewards and anyone not complying will be asked to leave.

Since 1955, a ban on divorcees entering the Royal Enclosure has been lifted. Undischarged bankrupts are still unwelcome and admission of ex-prisoners is at the discretion of officials.

So, if you've served time at Her Majesty's pleasure, don't tell. If you're bankrupt, don't tell and don't place a bet. And if you're divorced, it doesn't matter any more - as long as you're posh.

* Harry Mead is unwell.