In 2013, while helping her mother, Ingrid, comb through family possessions, Karin Wagner came across a large folio handwritten in German in the back of a dresser drawer. When Karin asked her mother what the document was, Ingrid replied, "Oh, that is your grandfather's Great War memoir."Schiller was a seventeen-year-old student in Bromberg, Prussia, when World War I broke out in August 1914. He enlisted in the German army and was assigned to an artillery unit on the Eastern Front. From 1915 to 1917, Schiller saw action in what is now Latvia, Lithuania, and Poland. After the Bolshevik Revolution in October 1917 and Russia's withdrawal from the war, Schiller was transferred to the Western Front. He arrived in time for Germany's last great offensive in the west, where the attempt to break the Allied lines included what is believed to be the single greatest artillery bombardment in human history up to that point. After the German retreat and Armistice, Schiller reentered military service in the Freikorps, German mercenary groups fighting in former German territory in Eastern Europe, where the conflict dragged on even after the Treaty of Versailles. Schiller left military service in May 1920.

Hans Schiller's Kriegserinnerungen (literally, "memories of war") was written in 1928 and based on diaries, since lost, that Schiller kept during the war. A Tale of Two Fronts, an edition of the memoir with historical context and explanatory notes, provides a vivid first-person account of German army life during World War I. It is a valuable resource for anyone interested in the experiences of common soldiers in World War I.