With the Sabines who occupied the middle mountain range from the borders of the Umbrians down to the region between the Tiber and the Anio, and who, at the epoch when the history of Rome begins, penetrated fighting and conquering as far as Latium itself, the Romans notwithstanding their immediate neighbourhood subsequently came comparatively little into contact. The feeble sympathy of the Sabines with the desperate resistance offered by the neighbouring peoples in the east and south, is evident even from the accounts of the annals; and - what is of more importance - we find here no fortresses to keep the land in subjection, such as were so numerously established especially in the Volscian plain. Perhaps this lack of opposition was connected with the fact that the Sabine hordes probably about this very time poured themselves over Lower Italy. Allured by the pleasantness of the settlements on the Tifernus and Volturnus, they appear to have interfered but little in the conflicts of which the region to the south of the Tiber was the arena.

Far more vehement and lasting was the resistance of the Aequi, who, having their settlements to the eastward of Rome as far as the valleys of the Turano and Salto and on the northern verge of the Fucine lake, bordered with the Sabines and Marsi[10], and of the Volsci, who to the south of the Rutuli settled around Ardea, and of the Latins extending southward as far as Cora, possessed the coast almost as far as the river Liris along with the adjacent islands and in the interior the whole region drained by the Liris. We do not intend to narrate the feuds annually renewed with these two peoples - feuds which are related in the Roman chronicles in such a way that the most insignificant foray is scarcely distinguishable from a momentous war, and historical connection is totally disregarded; it is sufficient to indicate the permanent results. We plainly perceive that it was the especial aim of the Romans and Latins to separate the Aequi from the Volsci, and to become masters of the communications between them; in the region between the southern slope of the Alban range, the Volscian mountains and the Pomptine marshes, moreover, the Latins and the Volscians appear to have come first into contact and to have even had their settlements intermingled[11]. In this region the Latins took the first steps beyond the bounds of their own land, and federal fortresses on foreign soil - Latin colonies, as they were called - were first established, namely: in the plain Velitrae (as is alleged, about 260) beneath the Alban range itself, and Suessa in the Pomptine low lands, in the mountains Norba (as is alleged, in 262) and Signia (alleged to have been strengthened in 259), both of which lie at the points of connection between the Aequian and Volscian territories. The object was attained still more fully by the accession of the Hernici to the league of the Romans and Latins (268), an accession which isolated the Volscians completely, and provided the league with a bulwark against the Sabellian tribes dwelling on the south and east; it is easy therefore to perceive why this little people obtained the concession of full equality with the two others in counsel and in distribution of the spoil. The feebler Aequi were thenceforth but little formidable; it was sufficient to undertake from time to time a plundering expedition against them. The Rutuli also, who bordered with Latium on the south in the plain along the coast, early succumbed; their town Ardea was converted into a Latin colony as early as 312[12]. The Volscians opposed a more serious resistance. The first notable success, after those mentioned above, achieved over them by the Romans was, remarkably enough, the foundation of Circeii in 361, which, as long as Antium and Tarracina continued free, can only have held communication with Latium by sea. Attempts were often made to occupy Antium, and one was temporarily successful in 287; but in 295 the town recovered its freedom, and it was not till after the Gallic conflagration that, in consequence of a violent war of thirteen years (365-377), the Romans gained a decided superiority in the Antiate and Pomptine territory. Satricum, not far from Antium, was occupied with a Latin colony in 369, and not long afterwards probably Antium itself as well as Tarracina[13]. The Pomptine territory was secured by the founding of the fortress Setia (372, strengthened in 375), and was distributed into farm-allotments and burgess-districts in the year 371 and following years. After this date the Volscians still perhaps rose in revolt, but they waged no further wars against Rome.

But the more decided the successes that the league of Romans, Latins, and Hernici achieved against the Etruscans, Aequi, Volsci, and Rutuli, the more that league became liable to disunion. The reason lay partly in the increase of the hegemonic power of Rome, of which we have already spoken as necessarily springing out of the existing circumstances, but which nevertheless was felt as a heavy burden in Latium; partly in particular acts of odious injustice perpetrated by the leading community. Of this nature was especially the infamous sentence of arbitration between the Aricini and the Rutuli in Ardea in 308, in which the Romans, called in to be arbiters regarding a border territory in dispute between the two communities, took it to themselves; and when this decision occasioned in Ardea internal dissensions in which the people wished to join the Volsci, while the nobility adhered to Rome, these dissensions were still more disgracefully employed as a pretext for the - already mentioned - sending of Roman colonists into the wealthy city, amongst whom the lands of the adherents of the party opposed to Rome were distributed (312). The main cause however of the internal breaking up of the league was the very subjugation of the common foe; forbearance ceased on one side, devotedness ceased on the other, from the time when they thought that they had no longer need of each other. The open breach between the Latins and Hernici on the one hand and the Romans on the other was more immediately occasioned partly by the capture of Rome by the Celts and the momentary weakness which it produced, partly by the definitive occupation and distribution of the Pomptine territory. The former allies soon stood opposed in the field.  Already Latin volunteers in great numbers had taken part in the last despairing struggle of the Antiates: now the most famous of the Latin cities, Lanuvium (371), Praeneste (372-374, 400), Tusculum (373), Tibur (394, 400), and even several of the fortresses established in the Volscian land by the Romano-Latin league, such as Velitrae and Circeii, had to be subdued by force of arms, and the Tiburtines were not afraid even to make common cause against Rome with the once more advancing hordes of the Gauls. No concerted revolt however took place, and Rome mastered the individual towns without much trouble.

Tusculum was even compelled (in 373) to give up its political independence, and to enter into the burgess-union of Rome as a subject community (civitas sine suffragio) so that the town retained its walls and an - although limited - self-administration, including magistrates and a burgess-assembly of its own, whereas its burgesses as Romans lacked the right of electing or being elected - the first instance of a whole burgess-body being incorporated as a dependent community with the Roman commonwealth.