An Aden civilian crouching in terror as British soldiers threaten him during Arabian demonstrations in Crater. (Photo by Express Newspapers/Getty Images). 1967

A worker pauses for a sandwich, resting on a girder during the construction of a skycraper. (Photo by Hulton Archive/Getty Images). Circa 1930

Three workers demonstrating the different types of gas masks used in mine rescue work. (Photo by Fox Photos/Getty Images). December 1925

Queen Elizabeth II (as Princess Elizabeth) writing at her desk in Windsor Castle, Berkshire. (Photo by Lisa Sheridan/Studio Lisa/Getty Images). 30th May 1944

View of an American marine as he lies in a foxhole and whistles at a husky, one of the scouting dogs used during the landing on Guam, August 1944. (Photo by W. Eugene Smith/Time & Life Pictures/Getty Images)

An American Marine readies to land on Guadalcanal during the five-month struggle for the island between late 1942 and early 1943. Three thousand miles south of Tokyo, Guadalcanal was a major shipping point for military supplies. The Allied victory there in February, 1943, marked a major turning point in the war after a string of Japanese victories in the Pacific. (Photo by Joe Scherschel/Time & Life Pictures)

A large bull walrus returns to the shores of Prins Karl Forland after diving and feeding on clams. (Photo by Paul Nicklen/National Geographic). Svalbard, Norway, 2011

A woman adjusts the Mantle of the Order of the British Empire at an exhibition at Buckingham Palace in London, Thursday, July 21, 2016. In celebration of Her Majesty's 90th birthday this year, visitors to the Summer Opening of the State Rooms at Buckingham Palace will enjoy an unprecedented display of The Queen's outfits, from childhood to the present day, in the special exhibition Fashioning a Reign: 90 Years of Style from The Queen's Wardrobe. (Photo by Frank Augstein/AP Photo)