Island and autonomous region (pop., 2001 prelim.: 1,599,511), Italy. Off the southern Italian coast, Sardinia is the second largest island in the western Mediterranean Sea. It measures 9,194 sq mi (23,813 sq km); its capital is Cagliari. Thousands of structures made of basalt blocks, called nuraghi, are a dominating feature of the island. These truncated conic structures of blocks taken from extinct volcanoes were built in prehistoric times without any mortar. Some date to c. 1500–400 BC. Phoenicians were Sardinia's first recorded settlers c. 800 BC. Greeks and Carthaginians followed; Roman rule began in 238 BC. In the early Middle Ages Pisa and Genoa struggled over its domination. The kingdom of Sardinia, centred on the lands of Piedmont in northwestern Italy and the island of Sardinia, was ruled by the house of Savoy from 1720 until the unification of Italy in 1861. Agriculture, fishing, and mining are economic mainstays of the island.