Cagliari (käˈlyärē) [key], city (1991 pop. 204,237), capital of Sardinia and of Cagliari prov., S Sardinia, Italy, on the Gulf of Cagliari (an arm of the Mediterranean Sea) and at the mouth of the Mannu River. It is the largest city in Sardinia and is a modern port and an industrial center. A flourishing Carthaginian city, it was taken by Rome in 238 B.C. Cagliari endured Arab invasions in the 8th and 9th cent. A.D. The city was a Pisan stronghold during the wars with Genoa (11th–14th cent.); its subsequent history is largely that of Sardinia. Cagliari was the site of a submarine base in World War II and was heavily bombed by the Allies. Noteworthy structures include the Romanesque-Gothic cathedral (13th cent.), the Basilica of San Saturnino (5th cent.), a large Roman amphitheater, and the massive tower of St. Pancras (built by Pisans in 1304).