Gombu was born in 1935 in Minzu, Tibet, the son of Lama Nawang Gyalzen — a monk and younger brother of the Dzongpen of Kharta and Lhamu Kipa the elder sister of Tenzing Norgay. This relationship was not approved by his parents because he came from an aristocratic family and she from a family of Serfs (workers on the Dzongpen's land). This led them to leave Tibet with a young Gombu and baby sister Doma and settle down in Khumjung in Nepal. As Gmbu grew up, he was sent to study as a monk in the Rongbuk monastery in Tibet but this was not a life Gombu would settle down for. After a year of studies (he recalls being beaten up for not memorizing his verses) he decided to run away from the monastery with a friend Ang Tshering. Under the cover of darkness they slipped through the outhouse and made their way back over the Nangpala Pass into Khumbu.
Back in Khumbu , Gombu would go searching for his uncle Tenzing Norgay who he heard had become a great Sirdar and climber. In 1952 Tenzing was part of the 1952 Swiss Everest Expedition and it was the first time Gombu met him. The following spring, Tenzing would take him for the British attempt on Everest and thus would began his tryst with destiny and his relationship with the mountains.
By now Tenzing's mountaineering experience and international contacts had made him a prestigious figure in the Sherpa community. He had already been asked to act as sirdar – head Sherpa – for the British attempt on Everest planned for the next spring and he would be deciding who got which jobs. Gombu begged to be included and was promised a place on the team, with the warning that it would be very hard work.
So, at the age of 17, Gombu became the youngest employee of the 1953 British Everest Expedition. Even by Sherpa standards he was short; he was also quite plump. One of the British team members, Wilfrid Noyce, commented that Gombu was the only Sherpa he had ever met who asked a sahib to go more slowly. It should be pointed out that Noyce was phenomenally fit, and that Gombu soon got into his high-altitude stride, endearing himself to the team. The leader, John Hunt, noted how "little Gombu was smiling and cherubic, like an overgrown schoolboy ... always seeking helpful jobs to perform." And when the big day came to lift 17 loads of food, fuel, tents and oxygen to the South Col for the final summit attempt, Gombu was one of the Sherpas chosen for this vital job.
A few days later his uncle reached the summit with Edmund Hillary, earning international fame not only for himself but to some extent for his whole Sherpa people, whose traditional trading activities had been curtailed by the recent Chinese invasion of Tibet. For a young Sherpa like Nawang Gombu, who had now proved himself at high altitude, a career in expeditions was a potentially lucrative, if dangerous, alternative to subsistence farming. In 1954 he was one of four Sherpas chosen to accompany Tenzing to Switzerland for alpine training with Arnold Glatthard at Rosenlaui, in the Bernese Oberland. That year he also attempted the world's fifth highest mountain, Makalu, with an American expedition. Then in 1955 he had his first big success, making the first ascent, with an Indian expedition, of the 7,518m Saser Kangri, in the glacial region of northern Ladakh later disputed so rancorously between India and Pakistan.
In 1960 he returned to Everest on the first Indian attempt, getting to within 100 tantalising metres of the summit. Then in 1963 Uncle Tenzing wrote to James Ramsay Ullman, the author commissioned to cover the first American Everest expedition, recommending Gombu as sirdar. Gombu got the job and 30 April that year found the 5ft Sherpa back on the summit ridge, above the South Col, sharing a tent with the 6ft 4in American climber Jim Whittaker. The following day, at 1pm, the two men planted the Stars and Stripes on the summit.
Success with the Americans widened Gombu's horizons. He was welcomed with the team at the White House by President Kennedy and received the Hubbard Medal of the National Geographic Society, to wear alongside his earlier Queen Elizabeth II Coronation Medal. Later, from 1973-93, Jim Whittaker invited him to spend summers working with his guiding company on Mount Rainier, Washington. Back in Asia he had made his permanent home in Darjeeling and become Director of Field Training at the Himalayan Mountaineering Institute, operating in Sikkim on the flanks of Kangchenjunga.
In 1964 he reached the summit of Nanda Devi, the highest mountain wholly in India, and the source of the Ganges. The following year he returned to Everest with the first Indian expedition to climb the mountain. This time the top camp was placed astonishingly high, just 350 metres below the summit, enabling Gombu and Capt AS Cheema to reach the top at 9.30am. Gombu had become the first person to climb Everest twice.
He married Sita Gombu, with whom he had a son and three daughters; one of them, Yangdu, now runs her own mountain trekking business based in Delhi. Gombu continued to climb well beyond middle age, making his last big expedition in 1989 to Kangchenjunga.
His sheer good nature and beaming smile endeared him to a wide international circle of friends and he remained particularly close to his American companions.