Following the break-up of the Soviet Union, Marx was regarded as a thinker doomed to oblivion about whom everything had already been said and written. However, the international economic crisis of 2008 favoured a return to his analysis of capitalism, and recently published volumes of the_ Marx-Engels-Gesamtausgabe_ (MEGA²) have provided researchers with new texts that underline the gulf between Marx's critical theory and the dogmatism of many twentieth-century Marxisms. This work reconstructs with great textual and historical rigour, but in a form accessible to those encountering Marx for the first time, a number of little noted, or often misunderstood, stages in his intellectual biography. The book is divided into three parts. The first – 'Intellectual Influences and Early Writings' – investigates the formation of the young Marx and the composition of his Parisian manuscripts of 1844. The second – 'The Critique of Political Economy' – focuses on the genesis of Marx's magnum opus, beginning with his studies of political economy in the early 1850s and following his labours through to all the preparatory manuscripts for _Capital_. The third – 'Political Militancy' – presents an insightful history of the International Working Men's Association and of the role that Marx played in that organization. The volume offers a close and innovative examination of Marx's ideas on post-Hegelian philosophy, alienated labour, the materialist conception of history, research methods, the theory of surplus-value, working-class self-emancipation, political organization and revolutionary theory. From this emerges “another Marx”, a thinker very different from the one depicted by so many of his critics and ostensible disciples.