Animals too have a tough time on the slopes of Everest. Here, yaks avoid a crevasse on their way down East Rongbuk Glacier
3/8
A member of a 1936 expedition tries to cross a crevasse
4/8
One of the most enduring mysteries of Everest is whether George Leigh Mallory and Andrew Irvine reached the summit before disappearing in 1922. Mallory’s boot was found intact with his body in May 1999
5/8
A view of the team that was part of a snowboarding expedition at Advanced Base Camp III
6/8
In 2001, American Erik Weihenmayer (centre), blind since the age of 13, became the first blind person to scale Everest. He had to rely on his teammates who would shout out instructions and warnings to help him make his way up
7/8
Tom Whittaker was the first disabled person—his right foot was amputated after an accident—to climb to Everest's summit. He described his ascent as a "climb of imagination, technology and human spirit"
8/8
Tenzing Norgay on the summit of Mount Everest on May 29, 1953 ( Photographs courtesy Roli Books, from the new book, Incredible Ascents to Everest by Sumathi Nagrath)