The Communist Left was defined by Lenin in Left Wing Communism, an infantile disorder, as an 'illness of youth' in the revolutionary period initiated in October 1917. History was to show, on the contrary, the prescience of those Left Communists of the 1920-30s who opposed work in parliament or the trade unions, or support for national liberation movements. Names like Gorter, Pannekoek, Bordiga and Pankhurst have become the historical emblems of that Left Communist current which remained faithful to internationalism even in the darkest days of the Second World War. The upsurge of proletarian struggle during the 1970s created a new interest in the Left Communist experience, especially amongst young militants who rejected the compromised parties of the bourgeois left. The high point of this experience was the series of conferences held between 1977 and 1980 in Milan and Paris. This book brings together for the first time in a single volume, the complete documents and proceedings of the three International Conferences of the Communist Left held between 1977 and 1980, plus those of the ‘Fourth Conference’ held in 1982. It includes documents translated for the first time into English. In the dark days of a dying capitalism, it is our hope that a new generation of militants will profit from the lessons both positive and negative to be drawn from this experience.