These images, scanned from old glass negatives which had surfaced in northern France, were believed to have been taken by a local amateur photographer in 1916. They showed British and a few Australian soldiers, in formal or informal poses, during or just before the most murderous battle in the history of the British Empire – Battle of the Somme. Who are these British and British Empire soldiers? The identity of the soldiers is, and may always remain, a mystery... (Property of Bernard Gardin/Dominique Zanardi/Joel Scribe/The Independent Magazine)

Indian Air Force soldiers toss their rifles as they perform during the full-dress rehearsal for Indian Air Force Day at the Hindon air force station on the outskirts of New Delhi October 6, 2015. (Photo by Anindito Mukherjee/Reuters)

Liu Chunxia, a supporter of Xu Zhiyong, one of China's most prominent rights advocates, is detained by policemen while she gathers with other supporters nearby a court where Xu's trial is being held in Beijing January 22, 2014. When dozens of activists unfurled banners across the country last March and April calling for officials to disclose their assets, they did so at the urging of one of China's most prominent rights advocates, Xu Zhiyong. Xu, 40, stands trial on Wednesday on a charge of “gathering a crowd to disturb public order” punishable by up to five years in prison. His case will almost certainly spark fresh criticism from Western governments over Beijing's crackdown on dissent. (Photo by Kim Kyung-Hoon/Reuters)

A man rides a horse at a playground on a hill in Kabul April 19, 2015. (Photo by Mohammad Ismail/Reuters)

A masked protester talks to a soldier during clashes after the funeral of Brig. Gen. Wissam al-Hassan October 21, 2012. Lebanese soldiers fired guns and tear gas to push back hundreds of protesters who broke through a police cordon and tried to storm the government headquarters in Beirut. (Photo by Hussein Malla/Associated Press)

Participants, one of them loosing balance, jump in a sack race at a shopping center in Paris to win a 500 euros voucher (537 USD), on the first day of the winter sales in Paris, France, Wednesday, January 6 , 2016. The five-week 2016 winter sales start everywhere across France on Wednesday Jan. 6 and end on Feb. 16. (Photo by Francois Mori/AP Photo)

A woman walks past graffiti in Beirut, Lebanon, Wednesday, May 4, 2016. Graffiti artists have been trying to re-engage disillusioned youth in a debate about the country's latest wave of political turmoil. (Photo by Hassan Ammar/AP Photo)

A car “crashed” into the ground at Hackescher Markt in Berlin, Germany on November 15, 2016, ahead of the launch of Jeremy Clarkson, Richard Hammond and James May's new show, “The Grand Tour”, on Amazon Prime Video, on Friday. (Photo by Clemens Bilan/Getty Images for Amazon Prime Video)