After the Napoleonic Era, nationalism emerged as the dominant ideology in Europe. In Italy several intellectuals and groups began to push the idea of a unified nation-state (see Risorgimento). At the time, the struggle for Italian unification was largely waged against the Austrian Empire, which was the hegemonic power in Italy and the single most powerful adversary to unification. The Austrian Empire vigorously repressed the growing nationalist sentiment among Italian elites, most of all during 1848 revolution and the following years. Italy finally attained independence in 1861; Venetia was annexed in 1866, and Latium, including Rome, in 1870.