Rudolf Rocker's classic survey of anarcho-syndicalism was written during the Spanish Civil War to explain to the wider reading public the ideology which inspired the social revolution in Spain. It remains unsurpassed as a general introduction to anarchist thought and an authoritative account of the early history of international anarchism by one of the movement's leading figures.

The present edition is unique in giving a complete facsimile reproduction of the 1938 edition as well as the corrected transcript of the epilogue to the Indian edition of 1947. It has the addition of a new biographical introduction by Nicolas Walter, in which he quotes from previously unpublished manuscript sources.