Mass mobilisation is usually considered a force for democracy and political liberalisation. Yet, many mass movements have explicit authoritarian or anti-liberal claims. When and why do such authoritarian mobilisation movements emerge, and who are the citizens that participate in this ``dark side of mobilisation''? While existing literature has focuses on the determinants and outcomes of pro-democracy movements, we know much less about the nature and drivers of movements with authoritarian or anti-liberal goals. Introducing new data on 200 years of anti-democratic mass mobilization across the world, we offer the first comprehensive mapping of the nature and determinants of these movements. Drawing on detailed data on the social categories and organizational bases of participants in these mobilization movements we investigate implications of theories pertaining to the social foundations of anti-democratic movements. We also revisit existing findings about the drivers of mass protest, showing that the factors triggering pro-democracy movements are not necessarily the same as those triggering mass mobilisation motivated by authoritarian sentiments.