Historical materialism is Karl Marx's theory of history. Marx locates historical change in the rise of class societies and the way humans labor together to make their livelihoods.For Marx and his lifetime collaborator, Friedrich Engels, historical materialism is the "view of the course of history which seeks the ultimate cause and the great moving power of all important historic events in the economic development of society, in the changes in the modes of production and exchange, in the consequent division of society into distinct classes, and in the struggles of these classes against one another."Although Marx never brought together a formal or comprehensive description of historical materialism in one published work, his key ideas are woven into a variety of works from the 1840s onward. Since Marx's time, the theory has been modified and expanded. It now has many Marxist and non-Marxist variants. Source: Wikipedia (en)