In August 1907, Amsterdam hosted an international anarchist congress with delegates from 14 different countries. Over the space of a week, it dealt with a series of questions, such as anti-militarism, anarchism and organization, anarchism and the workers’ movement, syndicalism and the general strike, etc., and also the foundation of a new anarchist international. These were, of course, the years immediately following anarchism’s so-called “terrorist phase”, when anarchists realized that they had to go back to their roots among the working people, where anarchism was born in the days of Bakunin’s First International. Of all the matters discussed in Amsterdam, the most important for the future development of the international workers’ movement were undoubtedly the relationship between anarchism and the new syndicalist movement and between the specific anarchist organization and the mass labour organizations. How should they interact with each other? Should anarchists participate in the workers’ struggles as members of a political organization? A century later, the various positions of anarchist militants and organizations have lost none of their value or polemic charge and serve as an excellent point of reference for all those today who are facing similar situations and asking the same questions. It is historical testimony of an indisputable value. The debates of the congress are enriched by Maurizio Antonioli’s introduction, which serves to place the congress is the correct historical context, highlighting the repercussions it would have on the social struggles at the time. The appendix on the 1905 Russian Revolution is also a mine of information and includes one of the most complete accounts available of the events in Russia. Maurizio Antonioli is a full Professor of Contemporary History in the Faculty of Political Sciences at the University of Milan. He has published numerous studies on the Italian labour movement (in particular on the metalworkers federation and on the Milanese and Lombard camere del lavoro), revolutionary syndicalism and anarchism, including: Armando Borghi e l'Unione sindacale italiana (1990), Pietro Gori, il cavaliere errante dell'anarchia (1995), Il sol dell'avvenire. L'anarchismo in Italia dalle origini alla Prima guerra mondiale (1999). He was also one of the editors of the Dizionario biografico degli anarchici italiani (2003-2004). Nestor McNab is a teacher and translator living in Rome, Italy. He has edited La Piattaforma Organizzativa dei Comunisti Anarchici—origine, dibattito e significato (2007) and has also translated pamphlets such as Anarchist Communists: A Question of Class (2005) and other material on behalf of the FdCA, of which he is a member.