For most of the year, Appleby is a sleepy little English market-town in eastern Cumbria, not that far from the Scottish border. Surrounded by green fields spotted with sheep, Appleby is dominated by a castle that overlooks a gently sloping high street flanked by small shops. It has lots of benches with old men on them, smoking pipes and mumbling about who has just died and what the weather was like in 1953.

Then June arrives. And with it, pandemonium.

First, one or two horse-drawn buggies arrive, clattering fast over the cobbles, weaving through the slowly moving traffic, driven by men in flat caps flicking long, thin whips. Then more buggies arrive, along with ornately painted Gypsy caravans drawn by cart-horses with solemn faces and huge hairy hooves.

And then the dam breaks.

In their thousands come trucks towing horse boxes, dilapidated caravans, gleaming aluminum trailers, cars that look as if they were roadworthy way back in the 1970s, spanking-new four-wheel-drive vehicles and horses. Lots and lots and lots of horses.

Appleby -- quiet, gentle, slowly moving Appleby -- is home to the largest horse fair in Europe and has been so ever since 1750 or thereabouts.

The original fair charter was granted in 1685. Things have been growing ever since -- although occasional wars between the Scots and the English have temporarily suspended play. It says something about the English art of understatement that the Appleby horse fair is known as "The New Fair" to distinguish it from other fairs held prior to 1685.

"There is nothing like it in scale or history," observes Keith Morgan, chairman of the Appleby New Fair Committee. "It changes the town completely."

And some!

In the days before political correctness began to suffocate the English language, the thousands of traders who gather here were called Gypsies. The name "Gypsy" is derived from Egypt, one possible place of origin of these wandering people. They would have called themselves Romanies (and still do), a name derived from another possible ancestral home in the dim mists of the past: Romania. Now they are called "Travelers" by the local tourist board (and by about three of the 30,000 tourists who flock to witness the spectacle).

Everyone else still calls them Gypsies.

Locals respond to this annual invasion in different ways. The shopkeepers erect temporary counters over their front doors. These effectively barricade their premises against shoplifters, while simultaneously enabling them to sell their wares and make significant profits. Local newspapers are keen to play up how important the fair is to the local economy and are hugely upbeat about the whole thing. Farmers and other conservative elements mutter bleakly about "dirty gyppos" (now that is politically incorrect!) and watch the increasingly raucous antics of the visitors with baleful eyes. Travelers have a reputation for stealing things. It's one reason why their presence is greeted with suspicion wherever they go. A mobile police station is set up on Salt Tip Corner, just by the bridge over the River Eden, and the police stop and search vehicles that appear to be stolen, un-roadworthy, driven by drunk drivers or loaded with stolen goods. The traffic wardens have a tremendous time and issue lots of parking tickets, for which they are rewarded with lots of abuse.

An information leaflet neatly sums up the experience: "The fair is not formally organized."

This is more English understatement. And it is one of the fair's finest attributes. It isn't sanitized, commercialized or regimented. It is organic, constantly changing, rooted in history. It's a place where anything can happen. In effect it is an immense clan-gathering of people who spend much of their lives on the move and would no more work in an office than they would pay taxes or acknowledge the drum that beats time to most of our lives.

It is wild. And it is a lot of fun.

Almost every horse that arrives is here to be traded, and they are put through their paces in startling ways. "Washing" involves the horses being rode down a rough wooden slide (erected by flinty-eyed officers of The Royal Society for the Prevention of Cruelty to Animals), and then through the river Eden, sometimes by women wearing very few clothes.

"Trotting" involves a hair-raising horse-drawn buggy charge and, unfortunately, this year there was a head-to-head encounter with a truck in which both riders, father and son, were killed, as was the horse.

Horse trading is fast and furious and involves a lot of arcane ceremony. Feathers are burned to seal deals. Some traders spit on their palms or through rings to transfer horse ownership.

A single horse can change hands 10 times in half as many days. Any of the many Gypsy fortune tellers can tell you that, and no matter what else they predict after you've crossed their palms with silver, on this subject they're bound to be right.

Most travelers encamp just outside of town, in a field known as Fair Hill or Gallows Hill, in honor of the public hangings that used to take place there (usually during the fair!). The field is just outside the borough boundary, enabling campers to avoid paying fees to the Appleby town council. Other Travelers camp in the lonely heathery moorlands that rise to the west of town. The smoke from their cooking fires rising into the clear, curlew-haunted skies is pure romance. The rubbish left behind, locals say (and this column must grudgingly agree), isn't.

If you are wondering why this column is describing an event that won't happen again for another 11 months, it is because now is the time to think about booking your accommodation in Appleby's historic and lovely inns. Leave it to any later, and you, too, may have to camp out on the moors for the first two weeks of June. And the local farmers won't like that -- they'll think you're a gyppo.