Frank McNally learns to distinguish a jennet from a jackass and the importance of being queen, in the timeless excitement of the annual fair at Killorglin

The scene in Frank Joy's garden is like a wedding shoot gone wrong. A cameraman wants the happy couple to move closer to each other. Gingerly, the 12-year-old girl in Celtic dress obliges, while the handsome but evil-smelling mountain goat is nudged towards her by handlers holding firmly to his horns.

The girl looks nervous. The goat looks nervous. But neither of them is as nervous as the Catholic Church - or so you'd think - when it contemplates the symbolism of Puck Fair.

This is of course a royal wedding. Niamh O'Connor is the Queen of Puck, and proud of it.

"It's been my dream since I was little," she said, having finally secured the role by winning an essay competition for sixth-class pupils in Killorglin's Scoil Mhuire.

It's a big deal for females in the town. Growing up without being Queen of Puck is a minor tragedy for a woman, like never having been a flower girl. As she began her official engagements yesterday, Niamh was given an emotional hug by an older sister.

"She always wanted to be queen but never got the chance," confided their mother.

The goat had no such aspirations. Ten days ago, he was minding his own business, preparing for the rutting season on a mountain in Glenbeigh, when he found himself caught up in the weirdest adventure of his life.

When he's returned to the wild later this week, truly he'll have something to tell the kids about. In the meantime, the diet of willow, ash, grass and cabbages to which he's entitled as King Puck is a small compensation for having to do live-to-camera pieces for Sky News.

Unlike the royal couple, Frank Joy could begin to relax yesterday. As official goat-catcher and keeper, he sleeps uneasily on the nights before the fair. When he took the job 15 years ago, wild goats were plentiful and press coverage scarce. Now there are far fewer of the former and much more of the latter. The photo shoots begin two weeks before Puck and he has to start searching for a goat several days before that.

He dreads his captive will escape or - God forbid - be kidnapped. He can imagine the phone call: "Pay up or the king gets it".

The goat is protected by an old rhyme: "The hand that kills King Puck/Will wither like the dew/The blade that cuts his whiskers/Will pierce your heart too/The rope that hangs old Puck/Will execute its maker. . ." But the curse has never been tested and it's not exactly comprehensive insurance.

As every guidebook notes, the origins of Puck Fair are lost in that famous meteorological phenomenon, the mists of antiquity.

The goat seems a guarantee of pre-Christian origins. But at least one historian has argued that that may have been a late - maybe 18th century - addition, influenced by English customs. It could be that the Puck's livestock fairs, for which royal patents go back to 1613, are the really ancient part of the event.

Today's cattle fair will be a dwindling vestige of its former self. But the "gathering day" horse fair is thriving, untroubled by the move off Killorglin's streets into a field. All equine life was there yesterday, from the imperious hunter with a price tag of €7,500 to a family of Shetland ponies, offered by a man from Banbridge for €300 each "and on down till I sell them".

Here, a workhorse nearly knocked you over with a backside the size of a bus. There, a jackass made his entry, braying like a fog-horn as he moved through the fair.

It was a minefield for the unwary. "Is that a jennet?" you asked a man standing beside a big black mare that had some horse characteristics but also had giant ears sticking out on either side like the tail wings of an aircraft. The man studied me with a mixture of contempt and sympathy. "You'll never see a jennet with a foal," he said. And right enough, the animal had a miniature version of herself attached. They turned out to be Spanish donkeys. Doh!

The star of the fair - in more ways than one - was a three-month-old foal and its mother, both spotted like Dalmatian dogs. Slightly bigger than the Shetland, the breed is called Mizen Star. The owner explained that you had to be sure the mare's pedigree went back "four of five generations", otherwise she could "throw a plain one".

A potential customer inquired about the price. €1,500 for the foal alone, €2,500 with its mother, the owner. Then a pause. "I'll take a bit less if oo're buyin'."

Last night's coronation marked the official start of festivities.

The goat was led through town in his royal carriage, accompanied by bands and floats, and then hoisted on to a 12-metre stand to begin his reign. "Goat rule" used to mean 24-hour drinking in Killorglin, a facility famously availed of on his honeymoon by Dylan Thomas. These days the bar extensions are limited. "Get Pucked till 3am" is one bar's slogan.

The days when this was predominantly a gypsy festival are gone too. Travellers are still an intrinsic part of it; their caravans ring the town and there are campfires at night, but it's not the annual meeting place it once was for those of no fixed abode.

For those whose home is Killorglin, meanwhile, Puck Fair rivals Christmas as a time when you meet old friends. "Happy Puck" they tell each other in Falvey's bar and other meeting places.

And if either one lives abroad, chances are they won't be crossing paths again for another 12 months.