Sardinia world (22 centenarians/100,000 inhabitants). Sardinia is the first discovered Blue Zone, a demographic and/or geographic area in the world with an oversize concentration of centenarians and supercentenarians. In 2016 there were 50,346 foreign national residents, forming 3% of the total Sardinian population. The most represented nationalities were: Sardinia's most populated cities are Cagliari and Sassari. The Metropolitan City of Cagliari has 431,302 inhabitants, or about ¼ of the population of the entire island. Eurostat has identified in Sardinia two Functional Urban Areas: Cagliari, with 477,000 inhabitants, and Sassari, with 222,000 inhabitants. Sardinia is one of the five Italian autonomous regions,
Kingdom of Sardinia of his son Victor Emmanuel II. In 1852, a liberal ministry under Count Camillo Benso di Cavour was installed and the Kingdom of Sardinia became the engine driving Italian unification. The Kingdom of Sardinia took part in the Crimean War, allied with the Ottoman Empire, Britain, and France, and fighting against Russia. In 1859, France sided with the Kingdom of Sardinia in a war against Austria, the Austro-Sardinian War. Napoleon III did not keep his promises to Cavour to fight until all of the Kingdom of Lombardy-Venetia had been conquered. Following the bloody battles of Magenta and Solferino, both French