Mount Everest, also known to Tibetans as Chomolungma, is the world's tallest mountain at 8,848 meters (29,029 feet). Until 1885 it was generally believed to be unclimbable, due to its extreme climate, remote location, and the lower atmospheric oxygen levels at the summit. The British mounted several attempts in the early 1920's, including the 1924 expeditions by George Mallory. Mallory and Andrew Irvine never returned from their attempt at the summit, and Mallory's body was not found until 1999. It is not known whether these men reached the summit.
On May 29, 1953, New Zealander Edmund Hillary and Nepali Tenzing Norgay officially reached the summit and returned safely. For some years the pair shared credit and refused to say who had reached the summit first, but in his later years Norgay revealed that it was Hillary.
As per the records - on 29th May 1953, Edmund Hillary from New Zealand and Sherpa Tenzing Norgay India became the first to reach the summit of Mount Everest.