At Large: Everest's ever-lasting effect on those who feel its force: A former SAS soldier has lost his toes and broken his neck in a glorious but painful obsession with the world's highest point

ONCE it was seen as unclimbable, impossible. Now more than 500 have scaled Everest, and as ever larger parties troop towards the summit, the world's highest peak has become derisively known as the Yak Track in climbing circles.

It is a mere 40 years tomorrow since Edmund Hillary and Tenzing Norgay made worldwide headlines by standing on the summit. But of the thousands who set foot on its slopes, only an elite few make the top. Despite fixed ropes on the harder sections and Sherpas to ferry most of the equipment, altitude and severe weather can beat even the best climbers.

John (Brummy) Stokes scaled Everest in 1976, becoming the fourth Briton to do so. An ex-SAS sergeant, Stokes made three further unsuccessful attempts on the mountain. He has seen his friends die there, lost all his toes after a harrowing all-night exposure at 28,000 feet, and broken his neck in an avalanche. Yet he still dreams of the snow-swept heights, where winds can reach 150 knots and the chill factor hits minus 70 degrees. What is the siren-song that still calls a man of 47, registered as disabled and in almost constant pain, to stand upon its inhospitable slopes again?

Stokes, who still lives in Hereford close to his former SAS base, should never have been a member of the 1976 Army Mountaineering Association expedition. But he had concealed so well the fact that his kneecap had been shot away in a desert war that he was chosen for a summit attempt with his close friend Michael (Bronco) Lane.

A small man who discovered the delights of climbing by scaling bridges over Birmingham canals as a youngster, Stokes still recalls his first sight of Everest during an unsuccessful attempt on nearby Nuptse (25,850ft). 'It was awe-inspiring. Although it was about 30 miles away, it was huge.'

A year later, he was just 1,500ft from the summit of Everest. But that night, the weather changed. 'It was avalanching on us and the tent was rattling and rolling. We thought we were going to come off, so we didn't get much sleep. The next day, we were told to come back down but I said 'There's only one way we're going, and it's not down'.'

The following day at 6am, the pair started to climb. 'We were on 45-degree avalanche-prone snow up to our thighs, and only making a couple of inches at a time. We had headaches and were feeling nauseous. You tell people that you climb because you enjoy it, but when it's like that and you're fighting for breath, there's nothing enjoyable about it, believe me.'

At the trickiest part, known as the Hillary Step, Stokes was crossing a ridge when the whole snow-covered section dropped 10ft. 'It took about 10 minutes before I could move again. All the strength drained from me.'

But by mid-afternoon, with nothing to see but swirling snow, the pair reached the summit. 'We were the highest people in the world. Nobody was higher except God. We were hugging and punching each other, and crying like babies. Even now, after all these years, I still get choked and feel the tears.' It was not the end of the story. 'When we got to about 28,000ft on the way down, it was getting dark and we couldn't move anyway. Too far to the left, and we would freefall 5,000ft into China, while a wrong move the other way and we would reach base camp 8,000ft below sooner than intended.

'We scraped a little hole in the snow. But about 1am, our oxygen ran out. It was cold, cold, cold. I was drifting away. I was dying. Bronco hit me to wake me. I did the same to him. We were keeping each other alive.'

Stokes found a little oxygen was left in his bottle, but could not undo the valve. Lane took off both gloves and loosened it. It kept them alive, but Lane was to pay a high price - the loss of his fingers from frostbite.

'As we shared the oxygen, Bronco suddenly passed it to his left, saying 'He wants some, too'. People say you hallucinate at that height, but it was no hallucination. We were in a cocoon and there was a third presence caring for us. Morning dawned on two far more religious people.'

As they struggled down, frostbitten and close to the limit of their endurance, they met John Scott and Pat Gunson, the second team to try for the summit. 'The weather had been so severe - they had five feet of snow at advance base camp - that they assumed we must be dead. John and Pat were just 1,000ft from the top and had a very good chance, but instead they chose to help us down. But for them, I'm not sure we would have made it.'

Snow-blind, his toes and nose frostbitten, it took Stokes four days to reach base camp. Later, all his toes were amputated. He started on the mountain weighing 11st and left it three and a half stone lighter.

Was it all worth it? He does not hesitate. 'Yes, I would go through it again,' he admits. And he did, overcoming the loss of his toes to lead an SAS team up the North Face of Everest, in 1984. But an avalanche (detailed in Everest*) wiped out advance base camp, killing one member of the party and breaking Stokes's neck.

He was back two years later in the first attempt across the pinnacles on the north-east ridge. But violent storms and avalanches forced them off the mountain. In 1988, Stokes's team became the first to climb across the pinnacles, but bad weather forced a summit attempt to be abandoned.

Stokes added: 'There is one route that no one has looked at, one aspect that has been in my mind for three years. I keep looking at the logistics of it. Yes, perhaps I will go back.' And somehow you know he will.

*Everest, edited by Peter Gillman, is published by Little, Brown on 27 May, pounds 25.