Lenin’s Imperialism is one of the most significant books of the twentieth century. Its significance arises not so much from the data it provides; nor does it arise from the sheer fact that it explains imperialism and the World War. The book is significant because it provides the steel-frame for a grand reconstruction of Marxism which becomes the basis for revolutionary praxis for the rest of the twentieth century. In his Introduction to this fresh edition, eminent Marxist economist Prabhat Patnaik places Lenin’s text in its historical context, explains its relevance, its impact on revolutionary praxis in the twentieth century, and situates Lenin’s theory of imperialism within the larger debate around this term that characterizes our own times.