From the 4th century BC onward, the western Mediterranean witnessed the transformation of Rome from a small city-state in Central Italy into a huge empire. In 510 BC, the Roman Republic was supposed to have come into existence. The date is disputed, because Roman historians made an effort to synchronize the history of Rome with that of Athens. Thus, it is rather suspicious that Rome got rid of its king in exactly the same year that Athens got rid of its turannos. But that the Etruscan rule over Rome came to an end, and that in the 5th century Rome operated independently, is a fact. Its survival was no foregone conclusion, though: it had to defend itself against other Latin cities, united with those cities in the Latin league against the Italian peoples who infiltrated into Latium from their mountain strongholds, and against the still very powerful Etruscan cities. Shortly after the start of the 4th century BC, there came on top of all these threats a Celtic invasion.
Around 400 BC, the expansion of Rome took off, with the capture of the Etruscan town of Veji, immediately to the north of the Tiber. The Roman territory doubled in size. The seizure of Rome by the Celts, who from the north penetrated deep into the Italian peninsula, around 390 BC, was a temporary setback. Fifty years on, Rome fought the Samnites in Campania, as an ally of the town of Capua; a bit later, they engaged in battle with the other Latin cities, which rose against the growing power of Rome, but they did so too late. The Latin League was dissolved in 338 BC, and most members were incorporated into Roman territory. Some, however, retained their independent status, officially as allies of Rome, but in reality completely under Roman power. Thus, the small Roman city-state started expanding: its territory, the ager Romanus, was steadily enlarged by annexing the territories of defeated cities. The inhabitants of such areas either got full Roman citizenship or a citizenship without political rights; but in both cases, the number of citizens (and the size of the Roman army) was increased. If some territory was not annexed but was granted independence, Rome considered this a favor in return for which the recipient had to show gratitude. This implied obedience: treaties concluded with such communities always stipulated that in matters of foreign policy and warfare, they had to defer to Rome. So Roman power grew along two lines: extension of Roman territory and the number of Roman citizens, and creation of a network of allies who were dependent on Rome.
World History
