Palio di Siena: Europe's finest sporting spectacles

A minute and a quarter was all it took – 77 seconds to be precise – but it was the most exhilarating, terrifying and triumphant spectacle I've ever witnessed. You can keep your cup finals and your rock concerts, your grand operas and your royal command performances. The Palio di Siena leaves them standing.

It is a horse race, but probably the strangest one in the world, and it has been conducted with the same elaborate intricacy since before Dante was born. To any tourist caught up in the crowds surging through Siena's steep and narrow medieval streets towards the Piazza del Campo – a huge, shield-shaped space in the centre of the city – it must be mystifying.

Anyone with a smattering of Italian would be even more confused, for the horses about to hurtle around the perimeter are identified not by their names (though they have them, and every citizen knows them) nor by their jockeys, but by strange animals and symbols: the goose, the shell, the dragon, the owl, the caterpillar, the ram, the wave, the tortoise and the she-wolf. And the enormous crowd in the middle of the piazza, and from every window and rooftop around it, will be shouting these words as if their very lives depended on the strength of their voices: "Onda!" they will roar, or "Bruca!", "Tartuca!" or "Civetta!"

The prize is the Palio itself: a huge banner of painted silk, created anew by different artists every year. There is no betting: the only money goes to the winning jockey and is produced by subscription from members of the winning contrada, who promised their personal contributions months ago. Only if their horse wins do they pay – but the glory of carrying the Palio back to their own museum is worth every last euro. Winning is all that matters. Second place is the worst possible disgrace, for the chance of victory was there, and has been missed.

There are 17 contrade, each located within the city walls. A contrada is a district, a community, a family, a clan, an emotion. Everybody in Siena and the surrounding villages belongs to one. Ideally, you are born in your parents' contrada, though if a difficult delivery takes a mother to hospital in another district, the father may bring soil from home to put under the bed. If you live outside the city, it is also possible to join one – and then, on a specific feast day, you are "baptised" into it. Dottoressa Giancarla Bindi, for example, lives beyond the walls and is a member of Oca (the goose).

Giancarla was our guide. We stayed at Pieve a Castello, 15 minutes away, where she arranged Italian lessons for our little group, bringing in two more teachers for our differing levels of (in)competence. And she led us through every serpentine twist of Sienese history, steadily illuminating its arcane mysteries.

The contrade are made instantly recognisable by their individual, brilliant colours – but the Sienese flag itself is austerely black and white. Mythology tells that the city was founded by the sons of Remus (brother of Romulus) who rode into the place with two horses: one black, one white. The sublime cathedral is made of layers of black and u o white marble: its bell-tower reaches up to the same height as the tower on the Palazzo Pubblico in the Campo. The symbolism is clear: a balance must always be maintained between the spiritual and the temporal, the religious and the secular, the sacred and the profane. Nothing illustrates this better than the Palio.

The race is dedicated to the Virgin Mary. It happens twice a year, once on 2 July, the feast of the Visitation, and on 16 August, the day after the Assumption. The latter date acknowledges her help in a Sienese victory over Florence in 1260, at the battle of Monteaperti; the former recalls an occasion when a statue of the Madonna di Provenzano deflected a bullet fired by a Spanish soldier and saved a Sienese life. A Mass is held before it starts, and the archbishop blesses the participants from his window by the cathedral. The first thing that happens when the July race is won is a " Te Deum" sung in the Provenzano church. In August the venue is the Cathedral, but the hymn is the same.

But the race is also a reminder of days of tournaments and military games fought out in the streets of the city, of jousts and even bull-fights. Although elaborate efforts are made to ensure that everything is fair and above board, it is no secret that enmities exist between various factions, and that jockeys are paid not merely to win – but to ensure that the enemy loses. They are issued with bull-hide whips as they enter the piazza for the race – but there are no restrictions on what they do with them. Other horses and jockeys are fair game. They wear tin helmets under their coloured silk caps. Ten contrade will compete, in strict rotation, for there is room for only 10 horses to run. Preparations begin months in advance, but tension really starts to mount in the last four days before the race, when the old terracotta stones around the edge of the Campo are covered by several layers of sand and water, creating a hard tufa that affords some grip to the horses.

Though it is a dizzyingly steep and angular course, serious accidents are rare. As my teacher, Raffaele, remarked, the jockeys are scarcely human: "If you or I fell from a horse in the Palio, we'd be a month in hospital: these fellows jump up and walk away." They certainly love their horses. Should one be injured, there is a special horse-hospice where every effort is made to restore it to health, and where it may eventually spend its declining years – sometimes as a mount for the disabled.

The next stage is for 30 or so animals to be put through their paces on the track. The Sienese watch avidly, in the piazza or on television, looking out for the likeliest runners. It is not so much speed that they need as agility and strong legs. And they tend to prefer mares or geldings, especially since 1999 when, as Giancarla elegantly put it "a stallion fell in love with a beautiful mare and just followed her".

Eventually, 10 horses are selected, numbered and paraded and the draw begins. Lots are drawn, and each horse is assigned to a contrada. A cheer went up when Chiocciola (the caterpillar) drew Brento, the favourite ride, and the Chiocciolini rushed down to take him away to their stable. Valdimontone (the ram) were pleased with their bay gelding, Elimia, while Oca (the goose) was less thrilled with Fedora Saura, a mare without much form. When all is settled, the horses are taken back to the contrade to be prepared.

After that, negotiations begin for the jockeys. They, too, need strong legs for they will ride bareback in slippery silk Andy Pandy suits on sweating horses. Again, some are favourites and everyone wants them. Each is known by a nickname –"ponytail", or "trinket" for example – and each has the right to choose his mount. Large sums are offered, and tentative choices made. After that come the trials, when the horses run again and again around this track, getting used to it, and allowing jockeys to change their minds, which they often do.

The night before the big day comes the prova generale, a kind of dress rehearsal. By now the horse Brento had – to general dismay – been injured by a faulty start and would not be running. The Caterpillar, not allowed a replacement, were devastated: 46 pages of the local paper were taken up by this incident.

The piazza was full, and the excitement great, yet the jockeys played games: some merely trotting, some galloping. It was indecisive, as we'd guessed it would be, and everyone dispersed cheerfully for a splendid dinner, each to his own contrada. We were invited to the contrada of Valdimontone (the Ram). Giancarla had taught us their special song, which was to be repeated again and again on that starry night. We sat down to a magnificent feast alongside more than 2,000 people all anticipating a triumph for the jockey (nicknamed "lo Zedde") and his mount Elimia, whose glorified image was projected behind the top table. We sang, we ate, we drank, then we sang again. We rolled home very late but, we suspected, long before it was all over. The concept of getting an early night is gloriously alien to the Sienese.

The next day, the great day, began with a very moving ceremony. Each contrada has an oratory, where both jockey and horse are blessed. The intense dignity of this little ceremony caught me by surprise. We were with Drago, (the dragon) their pretty horse Gezabele, and the jockey, nicknamed "Sgaibarre". When he'd finished, the priest touched a crucifix to the horse's head and sent them on their way, telling them to return victorious. They departed in silence, a few clapping tourists hastily shushed. I was amazed to find myself near to tears.

The big moment was approaching. Leaving the crowds pouring down an alley towards the piazza, we slipped through a little side door and up a steep marble staircase into a large room at the top of an ancient palace, where cold pink prosecco and canapés awaited us. Even better, there were two huge windows from which the entire square could be seen.

The corteo storico was just beginning. It is a phenomenal procession of great beauty. Just below us was the entrance through which they pass, all the contrade in magnificent medieval array with their drummer-boys, their flag-bearers, their guildsmen and their two flamboyant standard-bearers, who toss their silken standards high into the air, catch each other's, leap over them and flourish them aloft. Then comes a heavy horse dressed like a charger in coloured fabric, followed by the chosen racehorse itself, a light silk thrown across its back. We spotted Gezabele, flouncing again, and Elimia – but by now affection for Giancarla had led our loyalties towards the grey mare of the Oca (I'd even bought their scarf). Very slowly they all processed around that huge square, stopping frequently for more flag-throwing. The band repeatedly played a rousing, brazen march and the crowd cheered every new arrival.

Then came six enormous horses ridden by men in full armour, their visors down and their helmets surmounted by a cockerel, a bear, a lion and other symbols of the "dead" contrade, disbanded now but not forgotten. Finally came a huge cart drawn by four recalcitrant white oxen, bearing the Palio itself along with six men blowing silver trumpets. It was as if a painting by Uccello had come to life before our astonished eyes. And all the time, at the very top of the tower, one powerful man kept ringing a great deep bell called the Sunta.

And now at last, the waiting was over. The track was swept, cleared, inspected – and then the nine surviving runners pranced in, wired and fired to a pitch of almost uncontrollable excitement. All the ringing and cheering and drumming stopped as the whole place fell silent for the starter to announce the order in which they were to begin. The elegant coal-black horse of Lupa (the she-wolf) had pole position on the inside; the last to be called, Bruca (the caterpillar) was the wild card.

Leaning perilously out of the window, it was just possible to see the two ropes between which the first eight horses were supposed to stand in order. The Bruca rider was the famous Trecciolino, feared and respected uncrowned king of all the jockeys. His lot was to choose a moment when he considered the others were in line and a space was available to him. As they fidgeted, pushed at each other and occasionally lashed out, he waited and watched. Twice he darted forward: twice the ropes were dropped, twice the mortar was fired to indicate a false start, and they all returned with ever increasing agitation. It was almost unbearable. In the past, it had taken more than an hour to start the race: once or twice night had fallen and the whole thing had had to be postponed. Could that happen now?

Back they came, again they shilly-shallied into position while Bruca circled and watched for his moment. And then, quite suddenly, it arrived: the crowd saw the chance and roared; the ropes fell and they were away. First to fall was Lupa, but the horse sprang up and rejoined the race at speed – dangerously, for a riderless horse can win this race. Then, right below us, Elimia went down, "lo Zedde" curled into a ball but full in the path of six other horses. And he was indeed superhuman, for when they'd gone he simply got to his feet and strolled off.

And now the field was strung out and – hurray! – Oca was in the lead, the grey mare flying steadily onwards, her action smooth and sublimely beautiful. As they entered the third and final lap, only Nicchio (the shell) was any kind of threat but suddenly the riderless Lupa was in the way. Oca swung out wide and Nicchio seized his chance. They hurtled towards the finish together and, though we screamed and shouted for Oca, the Nicchio flag was hoisted.

We turned away – but suddenly a further roar rose from the crowd, and we rushed back to the windows. The flags had changed: an unmedieval photo-finish had decided it and Oca was the winner. It was a moment of pure joy.

As the grey mare, Fedora Saura, was led off in glory, the crowd drifted away, chattering. Tables appeared around the perimeter and soon another enormous party was underway. We sat out in the velvet night, toasting the victory of the goose. And I wondered if we'd ever come again. Perhaps they might stretch a point and allow one over-excited Englishwoman to join their magnificent contrada? It's worth a try.

GETTING THERE

Siena is easily accessed from Florence and Pisa airports. The former is served by Meridiana (0845 355 5588; www.meridiana.it) from Gatwick. A wider range serve Pisa: British Airways (0870 850 9850; www.ba.com) from Gatwick; easyJet (0905 821 0905; www.easyJet.com) from Gatwick and Bristol; Ryanair (0871 246 0000; www. ryanair.com) from Stansted, Bournemouth, Doncaster, Nottingham East Midlands, Glasgow and Liverpool; and Jet2 (0871 226 1737; www.jet2.com) from Belfast, Edinburgh, Manchester, Newcastle and Leeds/Bradford.

To reduce the impact on the environment, you can buy an "offset" from Equiclimate (0845 456 0170; www.ebico.co.uk) or Pure (020-7382 7815; www.puretrust.org.uk).

STAYING THERE

ATG of Oxford (01865 315678; www.atg-oxford.co.uk) offers an eight-day " Siena and the Palio" trip from £2,945 per person, including transfers, accommodation, Italian lessons, walks, tours and tickets to the Palio. The next available trip runs from 11 to 18 August.

VISITING THERE

The next Siena Palio takes place on 16 August (00 39 05 77 43875; palio.comune.siena.it).

MORE INFORMATION

Italian Tourist Board: 020-7408 1254; www.italiantouristboard.co.uk