Engels is considered by some scholars to be the inventor of Marxism. His work converted one of the most influential political movements of modern times. He not only developed dialectal and historical materialism - the official philosophies of history and science in many communist countries - but was also the first Marxist historian, anthropologist, philosopher and commentator on the early Marx. This book begins with an account of Engels' career as a radical journalist in Germany and England. Before he met Marx, he had established himself as a critic of industrialism and its effect on working people. By the time they joined forces he was already a convert to the communist cause. Together they promoted a distinctive point of view in philosophy and politics, summarized in the "Communist Manifesto", to which Engels made a substantial contribution. In his later years Engels developed his materialist interpretation of history, his chief intellectual legacy, which has had a major effect on the arts and social sciences. The author traces its source and its effect on the development of Marxist theory and practice, assesses its utility and discusses the difficulties which Marxists have encountered in defending it.