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.
Milan
On 18 March 1848, the Milanese rebelled against Austrian rule, during the so-called "Five Days" (), and Field Marshal Radetzky was forced to withdraw from the city temporarily. The Kingdom of Sardinia stepped in to help the insurgents; a plebiscite held in Lombardy decided in favour of unification with Sardinia. However, after defeating the Sardinian forces at Custoza on 24 July, Radetzky was able to reassert Austrian control over Milan and northern Italy. A few years on, however, Italian nationalists again called for the removal of Austria and Italian unification. Sardinia and France formed an alliance and defeated Austria at the Battle of Solferino in 1859. Following this battle, Milan and the rest of Lombardy were incorporated into the Kingdom of Sardinia, which soon gained control of most of Italy and in 1861 was rechristened as the Kingdom of Italy.