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.
Cagliari
Cagliari was the capital of the Kingdom of Sardinia from 1324 to 1848, when Turin became the formal capital of the kingdom (which in 1861 became the Kingdom of Italy). Today the city is a regional cultural, educational, political and artistic centre, known for its diverse Art Nouveau architecture and several monuments. It is also Sardinia's economic and industrial hub, having one of the biggest ports in the Mediterranean Sea, an international airport, and the 106th highest income level in Italy (among 8,092 comuni), comparable to that of several northern Italian cities.