This book analyses the evolving nature of democratic threats and identifies strategies necessary to safeguard democratic governance in an increasingly turbulent political environment. It explores how democratic systems in Europe have faced, and continue to face, threats from various entities that exhibit essential characteristics of being enemies of democracy, including fascism, Nazism, authoritarianism, and modern forms of populism and external interference. Through detailed case studies, the book examines the tactics used by enemies of democracy to undermine the sovereignty of political nations, from the rise of totalitarian regimes in the twentieth century to contemporary challenges like Russia’s democratic decline and hybrid warfare tactics in Poland and Estonia. It also highlights how certain democracies have successfully resisted these threats, offering valuable lessons for protecting democratic values and institutions in today’s world. Going beyond historical analysis, the book provides a comprehensive theoretical framework for understanding and categorising the enemies of democracy, transforming the concept from a normative idea into a powerful analytical tool. This book will be of key interest to scholars and students of European history and politics, political theory, democracy, political systems, political philosophy, and comparative politics.