William Ernest Powell Giles (1835-1897), best known as Ernest Giles, was an Australian explorer who led three major expeditions in central Australia. He did not attempt a regular exploring expedition until 1872, when with two other men he left Chambers pillar, South Australia (now in the Northern Territory), and traversed much previously untrodden country to the north-west and west. He made a fresh start on 4 August 1873 and was the first European to see the rock formations of The Olgas. Early in 1875 he prepared his diaries for publication under the title Geographic Travels in Central Australia, and on 13 March 1875, with the generous help of Sir Thomas Elder, he began his third expedition. In 1880 he published The Journal of a Forgotten Expedition, being an account of his third expedition, and in 1889 appeared Australia Twice Traversed. He was given the gold medal of the Royal Geographical Society in 1880.