The paper explores the history of Istria’s archival heritage between the nineteenth and twentieth centuries, showing how political change and national ideologies shaped the use of records. From Pietro Kandler’s early studies to the nationalist appropriation by Italian elites, documents became tools to assert an Italian identity against emerging Slavic movements. After WW-I, fascist policies reinforced this ideological use, while archives stayed under Italian local elite’s control. After 1945, amid shifting borders and displacement, they became contested symbols between Italy and Yugoslavia.