Causes of Depopulation.—What had previously, it seems, been a well-peopled region, with peasant proprietors, kept healthy by careful drainage, became in the 4th and 3rd centuries B.C. a district consisting in large measure of huge estates (latifundia) owned by the Roman aristocracy, cultivated by gangs of slaves. This led to the disappearance of the agricultural population, to a decline in public safety, and to the spread of malaria in many parts; indeed, it is quite possible that it was not introduced into Latium before the 4th century B.C. The evil increased in the later period of the republic, and many of the old towns of Latium sank into a very decayed condition ; with this the continual competition of the provinces as sources of food-supply no doubt had a good deal to do. Cicero speaks of Gabii, Labici and Bovillae as places that had fallen into abject poverty, while Horace refers to Gabii and Fidenae as mere "deserted villages," and Strabo as "once fortified towns, but now villages, belonging to private in dividuals." Many of the smaller places mentioned in the list of Dionysius, or tiie early wars of the Romans, had altogether ceased to exist, but the statement of Pliny that 53 communities (populi) had thus perished within the boundaries of Old Latium is perhaps exaggerated. By the end of the Republic a good many parts of Latium were infected, and Rome itself was highly malarious in the warm months. The emperors Claudius, Nerva and Trajan turned their attention to the district, and under their example and exhcrtation the Roman aristocracy erected numerous villas within its boundaries, and used them at least for summer residences. During the and century the Campagna seems to have entered on a new era of prosperity. The roads radiating in all directions from Rome were connected by a network of cross roads leading to the very numerous villas with which the Cam pagna was strewn and which seem in large measure to belong to this period. Some of these are of enormous extent, e.g., the villa of the Quintilii on the Via Appia, that known as Sette Bassi on the Via Latina, and that of Hadrian near Tibur, the largest of all. Latium Novum or Adjectum.—This comprised the terri tories of the Volsci and Hernici, a rugged and mountainous coun try, extending from the frontier of the Sabines to the sea-coast between Terracina and Sinuessa. But it was not separated from the adjacent territories by any natural frontier or physical bound aries. It included the Hernican cities of Anagnia, Ferentinum, Alatrium and Verulae—a group of mountain strongholds on the north side of the valley of the Trerus (Sacco) ; together with the Volscian cities on the south of the same valley, and in that of the Liris, the whole of which, with the exception of its extreme upper end, was included in the Volscian territory. Here were situated Signia, Frusino, Fabrateria, Fregellae, Sora, Arpinum, Atina, Aquinum, Casinum and Interamna; Anxur (Terracina) was the only seaport that properly belonged to the Volscians, the coast from thence to the mouth of the Liris being included in the terri tory of the Aurunci, or Ausones, who possessed the maritime towns of Fundi, Formiae, Caieta and Minturnae, together with Suessa in the interior, which had replaced their more ancient capital of Aurunca. Sinuessa, on the sea-coast between the Liris (Garigliano) and the Vulturnus, at the foot of the Monte Massico, was the last town in Latium. The Pons Campanus, by which the Via Appia crossed the Savo some 9 m. S.E. of Sinuessa, indicates by its name the position of the old Campanian frontier. In the interior the boundary fell between Casinum and Teanum Sidicinum, at about the moth milestone of the Via Latina—a fact which led later to the jurisdiction of the Roman courts being extended on every side to the moth mile from the city, and to this being the limit beyond which banishment from Rome was considered to begin.
The Apennines comprised within the boundaries of Latium form rugged mountain masses from 4,000 to 5,00a ft. high. In them three streams rise; (I) the Anio, now called Teverone, de scending from above Subiaco to Tivoli, where it enters the plain of the Campagna; (2) the Trerus (Sacco), rising below Palestrina (Praeneste) and flowing through a valley which separates the main mass of the Apennines from the Volscian mountains or Monti Lepini to join the Liris below Ceprano; (3) the Liris (Garigliano) which enters New Latium about 20 m. from its source and flows past Sora tortuously to the sea at Minturnae. The lower part of its wide valley is fertile, bordered with hills covered with vines, olives and fruit-trees, and well populated. Long after the Latins had ceased to exist as a separate people Roman writers used the phrase nomen Latinum, in a purely political sense, to designate the inhabitants of all cities on which the Romans had conferred "Latin rights" (jus Latinum), an inferior form of the Roman franchise, granted in the first instance to certain cities of the Latins when they became subjects of Rome, and later to many other cities of Italy, especially the so-called Latin colonies. Later still the same privileges were granted to places in other countries also—e.g., to most of the cities in Sicily and Spain. All persons enjoying these rights were termed in legal phraseology Latini or Latinae conditionis.
Several of the popes, as Sixtus IV. and Julius III., made un successful attempts to improve the condition of the Campagna, the former making a serious attempt to revive agriculture as against pasture, while in the latter part of the 16th century a line of watch-towers was erected along the coast. In the Renais sance, it is true, falls the erection of many fine villas in the neighbourhood of Rome—not only in the hills round the Cam pagna, but even in certain places in the lower ground, e.g., those of Julius II., at La Magliana and of Cardinal Trivulzio at Salone —and these continued to be frequented until the end of the i8th century, when the French Revolution dealt a fatal blow to the prosperity of the Roman nobility. The 17th and i8th centuries, however, mark the worst period of depopulation in the more malarious parts of the Campagna, which seems to have begun in the 15th century, though we hear of malaria throughout the middle ages. A new epoch was marked by the discovery of its cause. (See MALARIA, MOSQUITO.) The soil in many parts is very fertile, and springs are plentiful and abundant ; the water is in some cases sulphurous or ferruginous. In the winter it furnishes abundant pasture to herds of silver-grey oxen and shaggy black horses, as well as to some two million sheep, which pass in the summer to the mountain pastures of the Abruzzi. The shepherds, who live in conical huts, with their fierce dogs, are a characteristic feature of the Campagna. The wool is sold in Rome ; the sheep are milked and cheese (pecorino) and (ricotta) made. A certain amount of horse-breeding is done, and the Government has, as elsewhere in Italy, a certain number of stallions.
The modern "region" of Latium (Lazio) includes the four provinces of Frosinone, Rieti, Rome and Viterbo. (See ITALY.) The rise in its population since 1901 has been mainly due to the growth of that of the city of Rome, but also to the enlargement of the "region." See G. and F. Tomassetti, La Campagna romana (Rome, two) ; R. A. Lanciani, Wanderings in the Roman Campagna (London, 1909) ; T. Ashby, "The Classical Topography of the Roman Campagna," in Papers of the British School at Rome, i., iii.–v. (London, 1902), and The Roman Campagna in Classical Times (London, 1927).