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,
Vandal Sardinia Belisarius had defeated Gelimero on August 30, 533 and occupied Carthage. He was followed by Cirillus, who had failed to reach Sardinia. Tzazo and Gelimer, together with what remained of the army, marched against the Byzantines but were defeated at the Battle of Tricamarum, from Carthage. Tzazo was killed while Gelimero, escaping capture, surrendered a few months later. Cirillus then went to Calaris where he showed Tzazo's head impaled on a pike to the Vandals of the garrison, who immediately surrendered. Thus the Vandal era in Sardinia ended in 534 and the Byzantine period began. The Sardinian dioceses of the