Europe contained 36 million people classified as ethnic minorities in the interwar period. The vast majority, 25 million, lived in East Central Europe. With ultranationalism, xenophobia and racism rampant among the majority populations, this was a hotbed of the European minority question, where fragile democracies stood between Italian Fascism and German Nazism to the west and the Stalinist USSR in the east. Either right-wing authoritarianism or militant communism has often been seen as the only efficient enemies of fascism in the region. The introduction seeks to differentiate this image of Eastern and Central European anti-fascism, by emphasizing the role of ethnic minorities and their complex anti-fascist identities and memories. Still, any possible ethnic minority mobilization in the face of fascism must, we argue, be analysed in relation to the alternative solidarities offered by class-based identities that challenged ethnonationalist identities and frameworks. By looking at the interplay between ethnicity, class, and ideology in minority communities we offer a comprehensive analytical framework for the study of anti-fascism in ethnic minority communities. The introduction presents the fourteen case studies included in the volume and concludes with a general discussion on the ways in which anti-fascism could play a role in as well as counteract the construction of ethnic minority identities.