Born in 1890, Major Oliver Wheeler was a Canadian mountaineer who participated in the first British expedition to Mount Everest, in 1921. A battle-hardened veteran of the First World War, he served as the expedition’s surveyor, introducing the technique of photogrammetric mapping to the British mountaineering elite. While the more famous George Mallory has come to embody the heroic spirit of the early Himalayan pioneers, it was Wheeler who identified the route up Everest with his photographic surveys, thus making it possible for the mountain to finally be conquered a generation later.