Festival goers arrive for the Glastonbury festival at Worthy Farm, in Somerset, England, Thursday, June 23, 2016. (Photo by Guy Bell/Rex Features/Shutterstock)

A fighter of Libyan forces allied with the U.N.-backed government runs for cover during a battle with Islamic State fighters in Sirte, Libya, July 31, 2016. (Photo by Goran Tomasevic/Reuters)

LONDON - JUNE 04: A piece entitled “Entrance into wood” by Elke Krystufek goes on show at The Royal Academy Summer Exhibition on June 4, 2008 in London. In it's 240th year, the exhibition displays a wide range of recent work by both established and emerging artists. 10,000 artists submitted work for selection this year. (Photo by Peter Macdiarmid/Getty Images)

Egyptian bootblacks cleaning a European's shoes in Cairo. (Photo by Hulton Archive/Getty Images). Circa 1870

A four-year-old bulldog named Goldie wearing spectacles and a nightcap. (Photo by Fox Photos/Getty Images). 9th January 1960

Guests on the terrace of Shepheard's Hotel, Cairo, circa 1940. (Photo by Hulton Archive/Getty Images)