King Albert on Battle Field - Glass negative photogrpah. Public domain.

Photograph shows an aide-de-camp of King Albert I of Belgium picking up a souvenir on the Somme battlefield near Pozieres, France, May 16, 1917. King Albert I and General Hubert Gough, the British Commander of the Fifth Army stand in background. (Source: Flickr Commons project, 2015 and Imperial War Museums website: http://www.iwm.org.uk/collections/item/object/205077933)