Otto Hartmann, born perhaps around 1880, was a soldier in the Prussian Army during the First World War. Between March and October 1915, he served as a Vizefeldwebel [Staff Sergeant] with Landsturm [home defence] battalions, assigned to rear-guard duties with prisoners-of-war. At first he was stationed with 2. Companie of the 14. Landsturm Infanterie Ersatz-Bataillon at the Rennfeld prisoner-or-war camp in Münster. At the beginning of May, he was in Retowo in East Prussia, en route to Lithuania with 7. Companie, Halbbataillon Münster of the Landsturm Infanterie Regiment no. 1. Shortly, his company arrived at Rossienie [Raseiniai], staying there for several weeks. By the middle of July, Hartmann was attached to the Etappen of the Niemen armee [Army of ne Niemen]. His assignments took him west and north of Kovno [Kaunas], to Borki, Sredniki [Seredzius], Wilki [Vilkija], and Kieydany [Kedaniai], behind the operational front as it moved eastward. By mid-October, he had reached Janow [Jonava], north-east of Kovno. At this time some letters bore the stamp of 3. Kompanie of the Landsturm Infanterie Bataillon Schroda 1. Throughout these eight months, his wife Ada and their children Elizabeth, Fredy and Carl-Heinz lived in Minden, Westfalen [Westphalia], except for a period of time in the months of July and August, when they were visiting the family of Paul Voss in Solingen, Rheinland [Rhineland].