1970 British Annapurna South Face expedition

The 1970 British Annapurna South Face expedition was a Himalayan climb that was the first to take a deliberately difficult route up the face of an 8,000-metre mountain. On 27 May 1970 Don Whillans and Dougal Haston reached the summit of Annapurna I, which at 26,545 feet (8,091 m) is the highest peak in the Annapurna Massif in Nepal. Chris Bonington led the expedition, which approached up a glacier from the Annapurna Sanctuary and then used rock climbing techniques to put fixed ropes up the steep South Face. Although the plan had been to use supplementary oxygen, in the event it was not possible to carry any cylinders high enough for the lead climbers to use on their summit bid.

Lower down on the mountain, on 30 May, as the expedition was about to leave, Ian Clough was killed by a falling serac. Several members of the expedition rose to fame in Britain, and as a whole the expedition received international recognition in mountaineering circles on account of its innovative and extremely difficult nature.