Until today, the First World War represents a neglected aspect in Jewish history and historiography – even though the war itself hardly left a Jewish community unaffected. One effect of the war was the tremendous suffering of Jewish civilians in Eastern Europe. Another effect, especially for German Jews, was the encounter with East European Jews, or as the stereotype was termed, the Ostjuden. Many German-Jewish soldiers who served at the eastern front were now able to experience the life of the Jewish masses in the East firsthand. Before that many German Jews were oftentimes only familiar with Eastern Jews through anecdotes and descriptions. Contrary to many studies focusing on the liberal current within German Jewry, this essay concentrates on the images of East European Jews within the zionist and orthodox currents. This analysis thus asks in what way the images of East European Jews that were created by these two currents, served as a projection screen and a mirror for self-reflections of own identity constructions. While the discourse about Ostjuden had already existed before the outbreak and continued after the end of the First World War, the war itself, the developments abroad and at home, increasing antisemitism and fear of immigration of Ostjuden, but also a fascination with the authenticity of the Ostjude, could serve as a catalyzer of the discourse about Ostjuden. Hence, while stereotypes are usually conceived to be negative, the sources analyzed in this essay display existing positive stereotypes as well. First World War (1915-1918) Following a successful offensive in the late summer of 1915, the Central Powers, Austria-Hungary and the German Reich, divided Russian Poland between them. The military government of the Dual Monarchy, located in Lublin, constituted Austria- Hungary’s first and longest-lasting government of occupation. Although administered separately from the army at the front, it was still charged with standard military functions: securing peace, law and order, utilisation of provincial finance, as well as maintaining lines of communication. In addition the entire administration was initially taken over by civilian and military staff from the Dual Monarchy. The occupation of Poland was characterised by certain special features which distinguished it from other Austro-Hungarian military governments. One example is the effort made, notwithstanding its military functions, to win the hearts and minds of the population by employing Polish civil servants and military personnel from Galicia or by presenting themselves as a Catholic great power. By supporting Polish national consciousness they were, however, working in contravention of the terms of the Hague Convention as this was occupied Russian territory. Even by the end of the war no clear concepts for the future, which might have provided a rallying point for the population, had been developed. For one thing decisions were always taken with one eye on their German ally, for another there was an influential Polish lobby operating in the Imperial capital, Vienna. Disagreements with their German ally, arising from the separate administrations of the two occupied territories compounded the situation and led to increasing discontentment among the Poles in Austria and the Polish population as a whole.