The first book of the volume is devoted to the key problems of the “short 20th century”. The book examines demographic and migration processes, leading trends in the development of the world economy, and the specifics of the social transformations that have taken place over the course of a century. Considerable attention is paid to the main aspects of the development of world culture, problems of science and education, changes in the place and role of religion in the life of the individual and society. The origins, course, nature and consequences of the First World War, as well as the Versailles-Washington system of international relations that emerged as a result of it, are analyzed. The development of countries and regions of the world before the outbreak of World War II is characterized through the prism of transnational and global history. For historians and a wide range of readers.