Mount Everest is the uppermost mountain in the world. Its height of 29,035 feet (8,850 meters) was determined using GPS satellite equipment on May 5, 1999. It was before supposed to be slightly lower (29,028 feet /8,848 meters), as determined in 1954 by averaging measurements from a variety of sites around the mountain. The new height has been confirmed through the National Geographic Society.
The first seven attempts on Everest, initial with a reconnaissance in 1921, approached the mountain from Tibet, where a route to the peak via the North Col and North Ridge seemed possible. All were ineffective. George Mallory, who spearheaded the first three expeditions, lost his life with Andrew Irvine throughout a failed ascent in 1924.
Unsuccessful attempts continued through 1938, then halted throughout World War II. By the war's ending, Tibet had closed its borders, and Nepal, previously unreachable, had done the opposite.