Tsen Hai Sun and Hay Gy Sun, hanging by their hair beneath a hovering Bell helicopter, exchange gold rings in an unusual wedding ceremony in Hassloch, Pfalz, West Germany. (Photo by Keystone/Getty Images). 1979

A human skull keeps watch over US soldiers encamped in the Vietnamese jungle during the Vietnam War. (Photo by Terry Fincher/Getty Images). 1968

Victorian travellers trekking on the Chamonix Glacier in the Savoy Alps. (Photo by William England/Getty Images). 1867

North Vietnamese soldier, Nguen Thi-Hai, standing guard. (Photo by Keystone/Getty Images). 1968

Children jeer at British soldiers whiile a fire smoulders in the street behind them. (Photo by Keystone/Getty Images). 7th December 1971

A Viet Cong suspect holds his hands up after a Vietnamese Ranger from the 21st Vietnam Infantry Division routed him from his hiding place. (Photo by Keystone/Getty Images). 7th November 1967

English-born environmentalist and author Grey Owl (1888–1938) feeding a beaver. Born Archibald Stansfield Belaney in Surrey, he emigrated to Canada in 1906 and married a Mohawk woman. (Photo by Topical Press Agency/Getty Images). Circa 1930

The great lifting power of the French helicopter “The Lama” currently in production at the Marignana aircraft factory is displayed where it is lifting an Alouette Mark II. (Photo by Keystone/Getty Images). 1st January 1972

A monkey shakes hands with a woman at the Hotel des Singes in the Atlas Mountains. (Photo by Topical Press Agency/Getty Images). 1929

Loggers and their horses enjoying a lunchtime feed during tree felling at Scattersdells Wood, King's Langley, Hertfordshire. (Photo by Fred Morley/Fox Photos/Getty Images). 5th November 1937

Policemen arresting a demonstrator when fascists and communists clashed during a march led by British fascist Sir Oswald Mosley in London's East End. (Photo by Topical Press Agency/Getty Images). 4th October 1936

After taking part in a nurses' protest march from Speakers' Corner to Downing Street, Mary Chundee, Pat Veal (centre) and Tina Stone (right) prepare to hand in a petition to the Prime Minister, protesting about the pay and conditions of nurses working in Britain, 15th August 1968. (Photo by George W. Hales/Fox Photos/Hulton Archive/Getty Images)

American army combat platoon leader Second Lieutenant John Libs (center) of 2nd platoon, C Company, 2d Battalion, 16th Infantry Regiment, 1st Division, surveys the situation with his men from the relative safety of a watery rice paddy as they prepare to advance on a Viet Cong sniper position, Vietnam, mid 1960s. Libs and the rest of 2nd Platoon participated in the battle of Xa Cam My/Operation Abilene in April 1966 during which Charlie Company suffered 82% casualties. (Photo by Hulton Archive/Getty Images). 1965

Young man wearing fez, with three trained monkeys. (Photo by Charles Phelps Cushing/Retrofile/Getty Images). India, circa 1930s