Born on 18 August 1888, John de Vars Hazard spent much of his childhood in France and was educated at Bedford School before going on to study engineering. In his youth he took part in pioneering climbs in the Lake District, and made the first ascent of Great Gable's Abbey Buttress at Easter 1909. He joined the Royal Artillery and served in the First World War, during which he fought at the Battle of the Somme in 1916, as second in command to Henry Morshead, and was awarded the Military Cross. Morshead took part in the 1921 British Mount Everest reconnaissance expedition and the 1922 British Mount Everest expedition, and recommended that Hazard should be a member of the 1924 British Mount Everest expedition.