Mr Diemberger is the revered Austrian mountaineer and film-maker with whom Julie Tullis was climbing in 1986 when she reached the K2 summit only to die on the descent along with a second Briton, Alan Rouse.
In the face of the most appaling storms on the killer mountain, everyone believed Mr Diemberger had died too. Yet after five days and five nights, he managed to escape.
Yesterday he recalled that expedition and the conditions that have contributed to the deaths of more than 40 climbers. And he spoke of what drives mountaineers to reach for the top despite the ever-constant risk of death.
"We simply could not escape from the bad weather, we were prisoners of the storm. We got weaker and weaker. Only the two eldest people in the party survived. The others all died.
"I think we all thought we would probably die. We were five days and five nights in the storm at 8,000 metres in the top camp. In the end there was just a tiny chance to make it down."
On a previous expedition, he and Mrs Tullis had survived an avalanche in the Karakoram mountain range. "By a miracle, I was stopped between some blocks of ice and, as I was roped to Julie, she was also stopped and the avalanche went on and over us."
During the fateful expedition of August 1986 reports suggested he had been swept away by an avalanche - as appears to have happened to Alison Hargreaves - but in fact it was the weather which trapped them.
"Nobody could come up to help us because the storm was so terrible and the snow was so deep. If there's a heavy storm and you're outside the tent you're probably lost. In a storm, you cannot see where you go, all is white around you. That was the reason we couldn't come down. And if you're inside a tent you're a prisoner and the main problem is the cold."
Though so many mountaineers perish on the mountains which inspire them, the thought of Mrs Tullis's death still pains him. "I really have no words about it," he said, his excellent English almost failing him for the first time. "It was several years ago but you can see these events in your mind so clearly. I'll never forget."
All the mountaineers climbing in the Himalayas know there is a risk, even if they are careful. "You cannot exclude a certain portion of risk. You need fate on your side." But when this 63-year-old veteran speaks of mountains, it is easy to get a glimpse of what drove Ms Hargreaves on.
"Big mountains are a big addiction which makes you come back again and again. These mountains are really beautiful and K2 is one of the most beautiful mountains in the world. You all know that everybody can die there. But it is easy to understand that someone is so much in love with such a beautiful mountain that they simply cannot escape the draw of it. It's difficult to explain, it's not rational, it's sentiment that makes you go."
Mr Diemberger met Ms Hargreaves once about two years ago, at a book fair. He wrote K2, The Endless Knot about his expeditions, while she had written of her successful assault of all six northern faces of the Alps in just one summer. He remembers her as "strong and self-reliant" and liked her enormously.
"I hoped she would always have luck," he said yesterday. "I was sad to hear the news. You can die anywhere. But for people who love mountains, to die there is to die where your heart is. I think that's what I would like."Reuse content