Latium (lāˈshēəm) [key], Ital. Lazio, region (1990 pop. 5,170,672), 6,642 sq mi (17,203 sq km), central Italy, extending from the Apennines westward to the Tyrrhenian Sea. Rome is the capital of the region, which is divided into Frosinone, Latina, Rieti, Rome, and Viterbo provs. (named for their capitals). The region is mostly hilly and mountainous, with a narrow coastal plain, much of which has been reclaimed in the 20th cent. (see Campagna di Roma; Pontine Marshes). Agriculture forms the backbone of the regional economy; products include cereals, vegetables, grapes, olives, and fodder. Sheep and cattle are raised. Rome is Latium's main commercial, service, and industrial center. Industry in the region has been spurred (mid-20th cent.) by the construction of hydroelectric facilities on the Aniene and Liri rivers and a nuclear power plant at Latina. Manufactures include chemicals, cement, textiles, construction materials, and processed food. There is a large tourist industry, and fishing is pursued along the coast, especially at Civitavecchia, the region's chief port. In ancient times, Latium comprised a limited area E and S of the Tiber River that extended to the Alban Hills; only after it became part of Italy in 1870 did it approximately reach its present limits. In early Roman times Latium was inhabited by the Latins, the Etruscans (N of the Tiber River), and several Italic tribes. In the 3d cent. B.C., Rome subdued all of Latium. The fertile coastal plain became marshy, malaria-infested, and impoverished during the late Roman Empire and early Republic. After the fall of Rome, Latium was invaded in turn by the Visigoths, the Vandals, and the Lombards. From the 8th cent. the duchy of Rome, including most of modern Latium, belonged to the popes. Their authority was not always recognized in the towns, which were ruled at times as free communes or by local feudal lords. Except for the area S of Terracina, which belonged to the kingdom of Naples, Latium remained a part of the Papal States until 1870. In World War II, S Latium was the scene of bloody battles during the Allied drive on Rome (see Cassino; Anzio). There are two universities in Rome, which is also the site of the Vatican.