After the unsuccessful 1848 revolutions, conservative nationalism rose throughout Europe to threaten the liberal-humanist tradition. In Italy liberal and romantic movements-e.g. the Carbonari and Mazzini's Young Italy-failed to free the northern provinces from Austria and unify the disparate states. After 1848, the conservative Cavour modernized Piedmont-Savoy and sought to incorporate northern Italy into the kingdom. French support enabled Piedmont to acquire Lombardy, but forced it to give territory to France. In the south, Garibaldi's nationalist forces liberated Sicily, captured Naples, and advanced on Rome. Fearing Garibaldi's republicanism, Cavour ordered Piedmontese troops into the Papal States. Devoted to Italian unification, Garibaldi gave his conquests to Piedmont, and in 1861 Victor Emmanuel was proclaimed king of Italy. Italy completed unification by acquiring Ventia from Austria in 1866 and taking Rome from the papacy in 1870.

After the failure in 1848 of liberal German nationalism, conservative Prussia became the leading agent of unification. Earlier in the century, Prussia had adopted reforms designed to strengthen the state and maintain dominance of the military and the Junker class. It also advanced its economic position by assuming leadership of the Zollverein. In 1862 Bismarck became Chancellor and devoted himself to extending Prussian power. While thwarting liberals at home, Bismarck pursued an aggressive foreign policy, using militaristic nationalism as his principal tool. He provoked wars with Denmark and Austria that enabled Prussia to add new territories and to organize a North German confederation from which Austria was excluded. Victory over France enabled Prussia to gather in the remaining German states, and in 1871 William I was proclaimed Kaiser of a unified Germany. This new state upset the European balance of power, creating tensions that would erupt in World War I.

Multiethnic Austria confronted the irreconcilable nationalisms of it subject peoples. The Settlement of 1867 created a dual German-Magyar monarchy. The Magyars then began a program of Magyarization to force Magyar language and culture on non-Hungarians, suppressing all competing nationalist movements. In Bohemia Czech nationalists drew intense German hostility as they agitated for constitutional recognition. Serbian nationalists provoked the Austrian monarchy by working to gather the South Slavs of the empire into a Greater Serbia.

Paralleling these political developments was the growth throughout Europe of racial nationalism. Rejecting liberal principles, such nationalists embraced authoritarianism and militarism and worshipped the ethnic state. These sentiments were strongest in Germany, where they took the form of Volkish thought. Volkish thinkers looked to the Middle Ages for a glorious German past and envisioned an equally glorious future in which the German race would fulfill its special destiny. Other races were considered inferior, particularly Jews. These thinkers' special scorn for Jews was part of a larger current of anti-Semitism. Indulging in mythical thinking, anti-Semites across Europe demonized Jews as an evil race and blamed them for everything wrong with the modern world. Jewish nationalists countered this anti-Semitism with Zionism, but racial nationalism and anti-Semitism continued to strengthen, rejecting the Enlightenment tradition and laying the groundwork for Nazism in the twentieth century.