Encouraged by the conclusions to which the anthropologist Lewis H. Morgan had come in his studies on the evolution of the primitive society to the industrialized society, Engels decided to write this work to show the validity of the theses of historical materialism when explaining the transformations suffered in time by different societies throughout the world. From the early stages of the history of mankind ?? the periods of savagery and barbarism? up to the formation of the class society based on private property, Engels analyzes the evolution of the family and marriage, as well as the origin and nature of the State, emphasizing the relevance that economic avatars, power relations and the control of resources have had in all processes.