Edmund Hillary
Sir Edmund Percival Hillary (20 July 1919 – 11 January 2008) was a New Zealand mountaineer, explorer, and philanthropist. On 29 May 1953, Hillary and Nepalese Sherpa mountaineer Tenzing Norgay became the first climbers confirmed to have reached the summit of Mount Everest. They were part of the ninth British expedition to Everest, led by John Hunt.
Mount Everest
Reinhold Messner was the first climber to break the bottled oxygen tradition and in 1978, with Peter Habeler, made the first successful climb without it. In 1980, Messner summited the mountain solo, without supplemental oxygen or any porters or climbing partners, on the more difficult northwest route. Once the climbing community was satisfied that the mountain could be climbed without supplemental oxygen, many purists then took the next logical step of insisting that is how it "should" be climbed.