The experience of Salvador Allende's 1970-73 Popular Unity government in Chile is one of the most important and controversial in socialist history. Ruling class efforts to remove the Left from power were met by massive resistance and organization in workplaces across the country. While workers built councils and committees in their thousands, the Allende government recoiled from radicalizing the struggle, and the US-backed right prepared to impose a bloody dictatorship. This talk will attempt to track and explain the events of the Chilean struggle and take up the debates on the left about the causes of its tragic outcome.