5925367 Belgian troops constructing a shelter, 1914 (lantern slide) by Unknown photographer, (20th century); National Army Museum, London; (add.info.: Belgian troops constructing a shelter, 1914. Lantern slide, World War One, Western Front (1914-1918), 1914. Although Belgium?s small army resisted bravely against the invasion of 4 August 1914 it was soon overrun by the huge German force opposing it. Over 750,000 soldiers of the 1st, 2nd and 3rd Armies crossed the frontier to initiate the Schlieffen Plan, an invasion route through Belgium and into northern France. From a box of 70 lantern slides.); by National Army Museum ; out of copyright.