The rival sides climbed through the Hindu Kush like medieval armies, horse-mounted warriors leading thousands of fanatical followers, to do battle on a grassy highland arena. But this epic spectacle, which unfolded in Pakistan’s North West Frontier province, was a matter of sport, not war. And despite threats of dire violence, there wasn’t a Taliban fighter in sight.

Every summer polo teams from the mountain districts of Chitral and Gilgit converge on the Shandur Pass, a spectacular natural stadium surrounded by snow-sprinkled peaks which, at an altitude of over 12,000ft, is the world’s highest polo ground. The tournament dates back to the 1930s, when a British officer named Cobb formalised a centuries-old sporting rivalry. ‘The game of kings and the king of games,’ reads the sign at the entrance to Shandur. It remains a rambunctious, impassioned affair. Locals claim to have invented polo and their version – known as ‘freestyle’ polo – has little of the money, pomp or indeed rules of the more genteel game played in England.

The riders, rugged mountain men on sweat-soaked horses, thunder down the pitch, clinging precariously to their saddles and wielding mallets like sabres. Clashing, they swing their mallets like scythes, hitting man as often as ball. Assistants dash into the fray, risking injury to replace lost or smashed mallets. Noses are bloodied, horses tumble and, as the ball cannons towards the goal, the crowd rises to frenzied cheers. But if the rules haven’t changed in decades, circumstances have on the frontier. And this year the tournament was nearly cancelled.

Chitral is an island of peace in a province at war. In districts on every side – Dir, Swat and across the border in Afghanistan – Pakistani and western troops are battling the Taliban. The violence hasn’t spread to Chitral for partly ethnic reasons – it has a minority Pashtun population. But the idyllic valley has not entirely escaped the bitter crosswinds. Over the past year at least 20 Chitrali paramilitary soldiers have been killed in fighting elsewhere. Green Pakistani flags flutter outside houses in a mark of the bereaved.

Last week the district mayor, Maghfirat Shah, called on the government to scrap the festival, arguing it was disrespectful to the slain soldiers. Critics accused him of an ideological agenda: the mayor is a member of a religious political party that has virulently opposed the military operation. At a public rally days later his supporters issued a more sinister warning: that there could be a Taliban suicide attack. After intense backroom talks, and the deployment of extra security, the organisers prevailed.

‘They are just creating a fear factor,’ said Siraj ul Mulk, a member of the princely family of Chitral. ‘It’s precisely because of distractions like this that our people are not falling prey to the Taliban.’ In the end the crowd was smaller than previous years but equally fervent. A small tented city sprung up around the pitch, where 200 foreigners joined thousands of locals. The sponsors, a mobile phone company, provided Blackberry coverage.

And on the eve of the final, a full moon hovered in the starry sky as young men, some intoxicated, jigged and twirled to traditional, drum-driven music into the small hours.

The players, meanwhile, tried to sleep. Most are hardy amateurs – soldiers, teachers, policemen and watchmen, some in their 50s, few earning more than £80 a month. But the best are feted with premier league-style adulation. ‘If they win, the people give them their hearts,’ said Mazar Ahmed, a hoarse 19-year-old Gilgit fan. ‘For us, this is like the World Cup and 20/20 cricket all in one.’

The play holds dangers for man and animal. Bloodied faces are a common sight; the Gilgit captain, Meraj Alum, has a 10-stitch scar across his head. Yet he refuses to wear a helmet. ‘Gets in the way,’ he explained. For their steeds, though, the machismo borders on cruelty. Each horse must play a full 50 minutes – in regular polo they change every seven-and-a-half minutes – and, for some, the extreme altitude is too much. On Wednesday one horse collapsed of a heart attack and died. ‘It’s a bad rule,’ admitted ul Mulk. ‘It should be changed.’ No major politician turned up for the final so the chief guest was General Tariq Khan, the straight-talking head of the Frontier Corps paramilitary force. He doused any suggestion the tournament should end. ‘This is typical of these people with beards,’ he said of the polo opposition. ‘Men are dying because of people like them.’

In the end Chitral won the final, thrashing Gilgit by 10 goals to two – their fourth victory in a row. But there was one surprise – a visit from the rejectionist mayor, Maghfirat Shah. He appeared to have a change of heart, or a recognition of reality. ‘A great game,’ he said in a short half-time speech, ‘that sends a positive signal to the world.’ © Guardian News & Media Ltd 2009