"Realpolitik" is the notion that politics must be conducted in terms of the realistic assessment of power and the self-interest of individual nation-states (and the pursuit of those interests by any means, often ruthless and violent ones) and Cavour used it superbly. In 1855, as prime minister of Sardinia, he involved the kingdom on the British and French side of the Crimean War, using the peace conference to give international publicity to the cause of Italian unification. In 1858, he formed an alliance with France, one that included a pledge of military support if necessary, against Austria, Italy's major obstacle to unification. After a planned provocation of Vienna, Austria declared war against Sardinia in 1859 and was easily defeated by the French army. The peace, signed in November 1959 in Zurich, Switzerland, joined Lombardy, a formerly Austrian province, with Sardinia. In return, France received Savoy and Nice from Italy--a small price to pay for paving the way to unification.
Inspired by Cavour's success against Austria, revolutionary assemblies in the central Italian provinces of Tuscany, Parma, Modena, and Romagna voted in favor of unification with Sardinia in the summer of 1859. In the spring of 1860, Garibaldi came out of his self-imposed exile to lead a latter day Red Shirt army, known as the Thousand, in southern Italy. By the