A Mark IV tank, part of the parade at the Lord Mayor's Show in London. (Photo by Topical Press Agency/Getty Images). November 1917

Members of the French Foreign Legion arriving in Paris for a Bastille Day parade. (Photo by Fox Photos/Getty Images). July 13th 1939

This handout picture taken by Pleiades satellite and released on September 27, 2013 shows a small island of mud and rock created by the huge earthquake that hit southwest Pakistan has fascinated locals but experts – who found methane gas rising from it – say it is unlikely to last long. The 7.7-magnitude quake struck on September 25 in Baluchistan's remote Awaran district, killing at least 271 people and affecting hundreds of thousands. The island is about 60 to 70 feet (18 to 21 metres) high, up to 300 feet wide and up to 120 feet long and sits about 650 feet from the coast. (Photo by AFP Photo/CNES/Distribution Astrium Services)

A man from Dinka tribe holds his AK-47 rifle in front of cows in a Dinka cattle herders camp near Rumbek, capital of the Lakes State in central South Sudan December 14, 2013. (Photo by Goran Tomasevic/Reuters)

Long shadows are cast by players as Mitch Wallis of the Bulldogs passes the ball during the 2016 AFL Round 08 match between the Melbourne Demons and the Western Bulldogs at the Melbourne Cricket Ground, Melbourne on May 15, 2016. (Photo by Scott Barbour/AFL Media/Getty Images)

Indian Air Force personnel parade during the 85th Air Force Day celebrations at Hindon Air Force base in Ghaziabad on October 8, 2017. (Photo by AFP Photo/Stringer)

Two and a half year-old Jennifer Martin in tears during a visit to Santa at Harrods department store in London, 10th December 1949. (Photo by William Vanderson/Fox Photos/Hulton Archive/Getty Images)

A Hong Kong Correctional Services Dog Unit (CSDU) officer demonstrates training at the CSDU training facility in Stanley, Hong Kong, China, 27 February 2018. The Hong Kong CSDU consists of 29 staff members divided across six dog teams. According to the department's latest figure from 2017, the average daily penal population of Hong Kong was 8,529. (Photo by Jérôme Favre/EPA/EFE)