The era of world war and revolution in Europe was a time of unprecedented transformation. The four decades 1890–1930 constituted a sort of “Axial Age” of classical modernity, for most of the inventions and technological advances that made the difference between traditional life and the way in which modern people have lived ever since were first introduced or generalized during these years. Innovations included much broader use of electricity, the telephone, movies, automobiles, airplanes, the radio, refrigeration, and such basic conveniences as generalized indoor plumbing. Medical science also made vital breakthroughs. At the beginning of this period, most fatalities in warfare stemmed from disease; at its close, this was no longer true. There have been comparatively few decisive, absolutely new inventions since that time, for the computer was initially developed, and nuclear fission discovered, only a few years later.

There were similarly decisive innovations in politics, culture, and social organization. Political democracy first became a major feature of European life during this period, even though it met frustration or failure in many countries. The emergence of the masses altered social relations, accompanied by mass culture and mass politics. The origins of artistic “modernism” date from the mid nineteenth century, but modernism became a common artistic style only after the fin de siècle. Mass publicity and the arts of mass propaganda were introduced around the same time.