In the years between the two world wars a fledgling radical force that we today call ‘fascism’ was transformed from a tiny fringe movement into a dominant international political paradigm that challenged liberal ‘mainstream’ values and violently reversed decades of progressive change. Fascism’s spectacular and devastating success underlined how limited, resented, and reversible the alleged liberal consensus was in large parts of Europe during the interwar years; and how much demand for radical ultranationalist and authoritarian alternatives lay just below the fragile veneer of the liberal-democratic mainstream. The worldwide economic crisis was a catalyst for, rather than the primary cause of, this transformation, revealing and legitimising strong pre-existing concerns and resentments, both among the elites and public opinion.What is the relevance of this sombre historical precedent for contemporary Europe, haunted by perceptions of unprecedented existential, economic, and identity crises? How robust is the current mainstream consensus around liberal values and what kind of challenge does the continuing popularity of the radical populist right pose for ‘mainstream’ politics and society? More importantly, even if the new radical right still commands minority – though growing – support, are some of its extreme discourses becoming normalised and embedded into the mainstream?