Wikipedia: Socii: "The 75-year period between 338 BC and the outbreak of the First Punic War in 264 saw an explosion of Roman expansion and the subjugation of the entire peninsula to Roman political hegemony, achieved by virtually incessant warfare. Roman territory (ager Romanus) grew enormously in size, from c. 5,500 to 27,000 km², c. 20% of peninsular Italy. The Roman citizen population nearly tripled, from c. 350,000 to c. 900,000, c. 30% of the peninsular population. Latin colonies probably comprised a further 10% of the peninsula (about 12,500 km²). The remaining 60% of the peninsula remained in the hands of other Italian socii who were, however, forced to accept Roman supremacy...
...The expansion phase started with the defeat of the Latin League (338 BC) and the annexation of most of Latium Vetus. Subsequently, the main thrusts of expansion were southwards towards the Volturno river, annexing the territories of the Aurunci, Volsci, Sidicini and the Campanians themselves; and eastwards across the centre of the peninsula towards the Adriatic coast, incorporating the Hernici, Sabini, Aequi and Picentes.
The years after the departure of Pyrrhus in 275 saw a further round of annexation, of substantial territories in southern Italy at the expense of the Lucani and Bruttii. The Bruttii lost large forest lands, whose timber was needed to build ships and the Lucani lost their most fertile land, the coastal plain on which the Latin colony of Paestum was established in 273. In the North, the Romans annexed the ager Gallicus, a large stretch of plain on the Adriatic coast from the Senones Gallic tribe, with a Latin colony at Ariminum in 268. By 264, Rome controlled the entire Italian peninsula, either directly as Roman territory or indirectly through the socii.
The prevailing explanation for this explosive expansion, as proposed in W. V. Harris' War and Imperialism in Republican Rome (1979), is that the Roman state was an exceptionally martial society, whose every class from the aristocracy downwards was militarised and whose economy was based on the spoils of annual warfare. Rome's neighbouring peoples, on the other hand, were seen as essentially passive victims who strove, ultimately unsuccessfully, to defend themselves against Roman aggression. More recently, however, Harris' theory of Roman "exceptionalism" has been challenged by A. M. Eckstein, who points out that Rome's neighbours were equally militaristic and aggressive and that Rome was just one competitor for territory and hegemony in a peninsula whose interstate relations were largely anarchic and lacking effective mechanisms for resolution of interstate disputes. It was a world of continuous struggle for survival, of terrores multi for the Romans, a phrase from Livy that Eckstein uses to describe the politico-military situation in the peninsula before the imposition of the pax Romana. The reasons for the Romans' ultimate triumph was their superior manpower and political and military organisation.
Eckstein points out that it took 200 years of warfare for Rome to subdue just its Latin neighbours, as the Latin War did not end until 338 BC. This demonstrates that the other Latin cities were as martial as Rome itself. Before pax Romana, the Etruscan city-states to the north existed, like the Latin states, in a state of "militarised anarchy", with chronic and fierce competition for territory and hegemony. The evidence is that every Etruscan city until 500 BC was sited on virtually impregnable hilltops and cliff edges. Despite these natural defences, they all acquired walls by 400. Etruscan culture was highly militaristic. Graves with weapons and armour were common and captured enemies were often offered as human sacrifice and their severed heads displayed in public, as happened to 300 Roman prisoners at Tarquinii in 358. It took the Romans a century and four wars (480–390) just to reduce Veii, a single neighbouring Etruscan city.
To the South, the Samnites had a reputation for martial ferocity unrivalled in the peninsula. Tough mountain-dwelling pastoralists, they are believed to have invented the manipular fighting unit adopted by the Romans. Like the Romans, their national symbol was a wolf, but a male wolf on the prowl, not a she-wolf suckling babies. All graves of male Samnites contain weapons. Livy several times describes the barbarity of their raids into Campania. Their military effectiveness was greatly enhanced by the formation of the Samnite League by the four Samnite tribal cantons (the Caudini, Hirpini, Caraceni and Pentri). This brought their forces under the unified command of a single general in times of crisis.
It took the Romans three gruelling wars (the Samnite wars, 343–290 BC), during which they suffered many severe reverses, to subjugate the Samnites. Even after this, the Samnites remained implacable enemies of Rome, seizing every opportunity to throw off the Roman yoke. They rebelled and joined both Pyrrhus and Hannibal when these invaded Italy (275 and 218 BC respectively). In the Social War (91–88 BC), the Samnites were the core of the rebel coalition, and Samnite generals led the Italian forces.
The southern Greek city of Taras (Tarentum) had been founded by colonists from Sparta. They retained some of their founders' martial culture. With the best natural harbour in Italy and a fertile hinterland, it was faced from the start with fierce competition from the other Greek colonies and resistance from the indigenous Messapii, an Illyrian-speaking people that occupied what the Romans called Calabria (the heel of Italy). By around 350 BC, the Tarentine statesman Archytas had established the city's hegemony over both sets of rivals. The city's army of 30,000 foot and 4,000 cavalry was then the largest in the peninsula. Tarentine cavalry was renowned for its quality and celebrated in the city's coins, which often showed youths on horseback placing wreaths over their mount's head. The Tarentines' most important cult was to Nike, the Greek goddess of Victory. A famous status of Nike which stood in the city centre was ultimately transferred to the Senate House in Rome by the emperor Augustus.
The rise of Roman hegemony by three main means: (a) direct annexation of territory and incorporation of the existing inhabitants; (b) the foundation of Latin colonies on territory confiscated from defeated peoples; and (c) the binding of defeated peoples to Rome by treaties of perpetual alliance.
(a) Since the inhabitants of Latium Vetus were the Romans' fellow-tribesmen, there was no reluctance to grant them full citizenship. But annexations outside Latium Vetus soon gathered pace. The Romans then encountered the problem that their new subjects could, if granted full Roman citizenship, outnumber original Latins in the citizen body, threatening Rome's ethnic and cultural integrity. The problem as solved by introducing civitas sine suffragio ("non-voting citizenship"), a second-class status which carried all the rights and obligations of full citizenship except the right to vote. By this device, the Roman republic could enlarge its territory without losing its character as a Latin city-state.
The most important use of this device was the incorporation of the Campanian city-states into the ager Romanus, bringing the most fertile agricultural land in the peninsula and a large population under Roman control. Also incorporated sine suffragio were several tribes on the fringes of Latium Vetus that had until that time been long-time enemies of Rome: the Aurunci, Volsci, Sabini and Aequi.
(b) Alongside direct annexation, the second vehicle of Roman expansion was the colonia (colony), both Roman and Latin. Under Roman law, the lands of a surrendering enemy (dediticii) became the property of the Roman state. Some would be allocated to the members of a new Roman or Latin colony. Some would be held as ager publicus (state-owned land) and rented out to Roman tenant-farmers. The rest would be returned to the defeated enemy in return for the latter's adherence to the Roman military alliance.
The 19 Latin colonies founded in the period 338–263 outnumbered the Roman ones by four to one. This is because they involved a mixed Roman/original Latin/Italian allied population, and so could more easily attract the necessary number of settlers. But because of the mix, the settlers did not hold citizenship (the Romans among them lost their full citizenship). Instead, they were granted the iura Latina ("Latin rights") held by original Latins before their incorporation into the citizen body. In essence, these rights were similar to the civitates sine suffragio, except that the Latin colonists were technically not citizens, but peregrini ("foreigners"), although they could recover their citizenship by returning to Roman territory.
The question arises as to why the Latin colonists were not simply accorded citizenship sine suffragio. The answer is probably for reasons of military security. Classified as non-citizens, the Latins served in the allied alae, not the legions. There they could act as loyal "watchdogs" on potentially treacherous Italian socii, while the Romans/original Latins performed the same function in the legions on their sine suffragio colleagues.
The post-338 Latin colonies comprised 2,500–6,000 adult male settlers (average 3,700) based on an urban centre with a territorium of an average size of 370 km². The territorium would frequently consist of some of the defeated people's best agricultural land, since the social function of colonies was to satisfy the Romans' land-hungry peasantry. But the choice of site for a colonia was primarily dictated by strategic considerations. Coloniae were situated at key geographical points: the coasts (e.g. Antium, Ariminum), the exits to mountain passes (Alba Fucens), major road intersections (Venusia) and river fords (Interamna). Also colonies would be sited to provide a defensive barrier between Rome and her allies and potential enemies, as well as to separate those enemies from each other and keep watch on their activity: a divide-and-rule strategy. Thus Rome's string of colonies and eventual annexation of a belt of territory across the centre of the Italian peninsula was driven by the strategic aim of separating the Etruscans from the Samnites and interdicting a potential coalition of these powerful nations.
(c) However, the Romans generally did not annex the whole of the conquered enemy territory, but only selected portions. The defeated peoples generally retained the major part of their territory and their political autonomy. Their sovereignty was only limited in the fields of military and foreign policy, by a treaty with Rome which often varied in detail but always required them to provide troops to serve under Roman command and to "have the same friends and enemies as Rome" (in effect prohibiting them from waging war on other socii and from conducting independent diplomacy).
In some cases, no territory was annexed. For example, after the defeat of Pyrrhus in 275 BC, the Greek city-states of the South were accepted as Roman allies without any loss of territory regardless of whether they had backed Pyrrhus. This was due to the Romans' admiration of Greek culture and the fact that most of the cities contained pro-Roman aristocracies whose interests coincided with the Romans'. By the brutal standards of pre-hegemonic Italy, therefore, the Romans were relatively generous to their defeated foes, a further reason for their success.
A good case-study of how the Romans employed sophisticated divide-and-rule strategies in order to control potentially dangerous enemies is the political settlement imposed on the Samnites after three gruelling wars. The central aim was to prevent a restoration of the Samnite League, a confederation of these warlike tribes which had proved hugely dangerous. After 275 BC, the League's territory was split into three independent cantons: Samnium, Hirpinum and Caudium. A broad belt of Samnite territory was annexed, separating the Samnites from their neighbours to the north-the Marsi and Paeligni. Two Latin colonies were founded in the heart of Samnite territory to act as "watchdogs".
The final feature of Roman hegemony was the construction of a number of paved highways all over the peninsula, revolutionising communication and trade. The most famous and important was the Via Appia, from Rome to Brundisium via Campania (opened 312 BC). Others were the Via Salaria to Picenum, the Via Flaminia from Rome to Arretium (Rimini), and the Via Cassia into Etruria...