After the defeat of Napoleon in 1815, Europe entered a period of relatively stable peace. Initiated at the Congress of Vienna, the conservative powers led by Metternich in Austria developed a European geopolitical system based on the maintenance of the status quo and designed to avoid war through a balance of powers that eliminated the threat of any one nation gaining extreme strength by ensuring the relative strength of that nation's adversaries. The balance of power held through 1870, with brief periods of revolt in 1830 and 1848 that sprang from class differences exacerbated and made obvious by the industrial revolution. The revolts of 1830 and 1848 were also generated by the clash of ideologies present through the mid-nineteenth century. While 1815-1848 is often (and not incorrectly) characterized as teetering between conservatism and liberalism, it also saw the rise and maturation of radicalism, romanticism, nationalism, and socialism. Though the 1830 and 1848 revolts were quickly suppressed by the conservative powers, they did demonstrate a general trend toward an increasingly active working class desirous of economic and political power. In 1870 and 1871 Italy and Germany became unified nations, with Germany in particular emerging as an immediate international force.
The years between 1871 and 1914 brought liberal progress in England, social welfare in Germany, imperial expansion throughout the world, the spread of European civilization, and economic strengthening of England, Germany, the United States, and Japan. Newspaper editors and cultural pundits referred to these years contemporaneously as the "dawn of a new era" in scientific development, peace, economic expansion, and cultural civilization. Without war or major conflict in sight, Europe set out to perfect its home and spread its perfection throughout the world. The order of the day was, quite simply, self- improvement, national improvement, and attainable perfection; the great successes of Europe during these years seemed to prove that such was possible. Unfortunately, certain paternalistic policies developed out of such a perspective. While we cannot apologize for brutal treatment of Africans and Asians during the imperial period, we can understand such practices as the manifestations of a European polity that thought it was implementing the true inheritance of its liberal heritage. Further, though no major war seemed to threaten, the forty years after 1871 erupted in World War I, a catastrophic war that tore through Europe with a brutality unanticipated by any of its combatants. Any study of the period between 1871 and 1914 must be made with an eye to 1914, and the massive, transformative war that year held.
Revolution and the growth of industrial society, 1789–1914
Developments in 19th-century Europe are bounded by two great events. The French Revolution broke out in 1789, and its effects reverberated throughout much of Europe for many decades. World War I began in 1914. Its inception resulted from many trends in European society, culture, and diplomacy during the late 19th century. In between these boundaries—the one opening a new set of trends, the other bringing long-standing tensions to a head—much of modern Europe was defined.
Europe during this 125-year span was both united and deeply divided. A number of basic cultural trends, including new literary styles and the spread of science, ran through the entire continent. European states were increasingly locked in diplomatic interaction, culminating in continentwide alliance systems after 1871. At the same time, this was a century of growing nationalism, in which individual states jealously protected their identities and indeed established more rigorous border controls than ever before. Finally, the European continent was to an extent divided between two zones of differential development. Changes such as the Industrial Revolution and political liberalization spread first and fastest in western Europe—Britain, France, the Low Countries, Scandinavia, and, to an extent, Germany and Italy. Eastern and southern Europe, more rural at the outset of the period, changed more slowly and in somewhat different ways.
Europe witnessed important common patterns and increasing interconnections, but these developments must be assessed in terms of nation-state divisions and, even more, of larger regional differences. Some trends, including the ongoing impact of the French Revolution, ran through virtually the entire 19th century. Other characteristics, however, had a shorter life span.
Some historians prefer to divide 19th-century history into relatively small chunks. Thus, 1789–1815 is defined by the French Revolution and Napoleon; 1815–48 forms a period of reaction and adjustment; 1848–71 is dominated by a new round of revolution and the unifications of the German and Italian nations; and 1871–1914, an age of imperialism, is shaped by new kinds of political debate and the pressures that culminated in war. Overriding these important markers, however, a simpler division can also be useful. Between 1789 and 1849 Europe dealt with the forces of political revolution and the first impact of the Industrial Revolution. Between 1849 and 1914 a fuller industrial society emerged, including new forms of states and of diplomatic and military alignments. The mid-19th century, in either formulation, looms as a particularly important point of transition within the extended 19th century.