Having started climbing in the Alps while a student at Queens', he was the youngest climber on the 1953 British expedition to Mount Everest on which Edmund Hillary and Tenzing Norgay made the first ascent of the mountain. Two years later, in 1955, he and Joe Brown became the first climbers to ascend Kangchenjunga, the third highest mountain in the world. Out of respect for the religious feelings of the people of Nepal and Sikkim, they stopped about ten feet below the actual summit.