This book is a study of political exile and transnational activism in the late-Victorian period. It explores the history of about 500 French-speaking anarchists who lived in exile in London between 1880 and 1914, with a close focus on the 1890s, when their presence peaked. These individuals sought to escape intense repression in France, at a time when anarchist-inspired terrorism swept over the Western world. Until the 1905 Aliens Act, Britain was the exception in maintaining a liberal approach to the containment of anarchism and terrorism; it was therefore the choice destination of international exiled anarchists, just as it had been for previous generations of revolutionary exiles throughout the nineteenth century. These French groups in London played a strategic role in the reinvention of anarchism at a time of crisis, but also triggered intense moral panic in France, Britain and beyond.