History of Sardinia
In the Early Middle Ages, through barbarian movements, the waning of the Byzantine Empire influence in the western Mediterranean and the Saracen raids, the island fell out of the sphere of influence of any higher government. This led to the birth of four kingdoms called "Judicates" (Latin: "Judicati"; Sardinian: "Judicados") in the 8th through 10th centuries. Falling under papal influence, Sardinia became the focus of the rivalry of Genoa and Pisa, the Judicates and the Crown of Aragon, which eventually subsumed the island as the Kingdom of Sardinia in 1324. The Kingdom was to last until 1718, when it was ceded to the Piedmontese House of Savoy; later, in 1861, it would thus become the Kingdom of Italy and finally in 1946 the Italian Republic.
Italian unification
The 2nd War of Italian Independence began in April 1859 when the Sardinian Prime Minister Count Cavour found an ally in Napoleon III. Napoleon III signed a secret alliance and Cavour provoked Austria with military maneuvers and eventually created the war in April 1859. Cavour called for volunteers to enlist in the Italian liberation. The Austrians planned to use their army to beat the Sardinians before the French could come to their aid. Austria had an army of 140,000 men, while the Sardinians had a mere 70,000 men by comparison. However the Austrians' numerical strength was outweighed by an ineffectual leadership appointed by the Emperor on the basis of noble lineage, rather than military competency. Their army was slow to enter the capital of Sardinia, taking almost ten days to travel the . By this time, the French had reinforced the Sardinians, so the Austrians retreated. 
Napoleon III's plans worked and at the Battle of Solferino, France defeated Austria and forced negotiations. The settlement, by which Lombardy was annexed to Sardinia, left Austria in control of Venice. 
Sardinia eventually won the Second War of Italian Unification due to statesmanship instead of armies or popular election. The final arrangement was ironed out by "back-room" deals instead of in the battlefield. This was because neither France, Austria, nor Sardinia wanted to risk another battle and could not handle further fighting. All of the sides were eventually unhappy with the final outcome of the 2nd War of Italian Unification and expected another conflict in the future.