Conclusion
A meteoric rise from struggling city-state to regional power occurred at Rome during the fifty years following 400 BC. The turn of the century had found Rome bound in an effective alliance with the smaller Latin poleis and the Hernician tribal state of the Trerus valley; a league that in the previous decades had allowed the Rome to drive-off and blunt the threat of the Osco-Sabellian invasions of Latium. Although wracked with ongoing political and economic crises, the city could when necessary find the compromises required to move the evolution of the republic forward: a flexibility born of the great need to show solidarity in a war-torn and anarchic neighbourhood. The Romans could therefore boast at 400 BC of a well-organized government and army, geared for conducting efficient and effective yearly military campaigns against an array of enemies. To fight these ongoing wars, the Roman state could draw on a large and ever-expanding population of citizen-soldiers; an abundance resulting from the city's strategic location astride major inland trade routes and a placement amidst some of the best agricultural land in Italy. The Romans of this time were inured to both the toil of farming and the hardship of war and these two pursuits engendered in them virtues and characteristics necessary for their prosecution: perseverance, practicality, courage, discipline, harshness. One need only read the traditions of Cincinnatus and Camillus, pulled from their farms to lead Rome's legions to victory, to understand those qualities and pursuits most revered and respected among the old Romans.
The ten years of the 390's witnessed two critical events in Roman history: the conquest of Veii in 396 BC and the Gallic sack of 390 BC. The former event marked a huge increase in Rome's size and power relative to its neighbours, while the latter was a horrific disaster that shook the city to its foundations and resulted in the end of the Latin-Hernician alliance. From 389 BC Rome was on its own in its neighbourhood. Even the conquest of new territory did not immediately solve long-standing crises of land-usage, debt and political power that had persisted for generations; instead the Gallic sack intensified them. Rome's answer to these problems was the same one Athens had made following the Persian sack: achieve security through conquest and expansion. Thus the Romans after 390 BC went on the offensive in all directions and against all its neighbours, even its former allies. While conducting these conquests, the city was also able to address in a significant way its internal problems, by the enactment the Licinio-Sextian laws. These laws included measure meant to alleviate the issues of land, debt (and debt-slavery) and political power-sharing between the patrician and plebian orders. The alleviation of these problems, the state was able to stabilize its internal affairs and hence concentrate better on its foreign policy.
The four decades from 390 BC are a testament to the rapidly increasing population and power of Rome. Every year, multiple legions were enrolled and sent off to fight, many times against several enemies at once. By 343 BC, the eve of the great war with Samnium for the mastery of Italy, the Romans had crushed and subdued all of their neighbouring enemies. The Aequi were gone, entirely erased from the record, the Volsci driven to toe-holds on the coast and at the southern corner of the Monti Lepini, the Latins and Hernici defeated and brought under Roman hegemony, the Etruscans pushed back to the far side of the Monti Cimini and the Faliscans violently evicted from much of their lands. Even the Gauls, who had burned Rome to the ground in 390 BC, were dealt stinging reverses when they attempted further inroads into Latium. Rome had now become the greatest power in Tyrrhenian Italy; its policies generating a virtuous cycle of conquest, economic expansion and added power. The city's final achievement was to organize its conquests into a functioning and governable web of sovereign lands, colonies and dependant allies. More struggles were indeed to come, but a measure of security not previously known had been built up and solid foundations for further success laid out.