This special issue of the journal zeitgeschichte presents the results of the doctoral theses written within the framework of the Doctoral College European Historical Dictatorship and Transformation Research (2009-2012) as selected scholarly essays. The contributions are devoted to authoritarian regimes of the 20th century in Austria, Belarus, Greece, Hungary, Italy, Latvia, Lithuania, Poland, Portugal, Romania, Spain, and the Soviet Union. Using various methods from the humanities and social sciences, different aspects of mainly small dictatorships are examined: conditions of emergence, structures, continuities, as well as preceding and subsequent processes of political and social transformation.