This rigorous yet readable study shows how the anarchist movement arose out of the debates and conflicts within the First International. It tracks how anarchist tendencies in the International became more pronounced over time, often going head-to-head with the Marxists in struggles over how best to achieve freedom and equality for workers. It provides an important corrective to much of the scholarship on this topic, as most English-language histories of the First International have been written from a Marxist perspective.